diff --git a/lib/src/generator/templates.aot_renderers_for_html.dart b/lib/src/generator/templates.aot_renderers_for_html.dart
index e1bc51d496..7ce439efda 100644
--- a/lib/src/generator/templates.aot_renderers_for_html.dart
+++ b/lib/src/generator/templates.aot_renderers_for_html.dart
@@ -7,7 +7,6 @@
 // the variable is not used; generally when the section is checking if a
 // non-bool, non-Iterable field is non-null.
 // ignore_for_file: unused_local_variable
-// @dart=2.9
 // ignore_for_file: non_constant_identifier_names, unnecessary_string_escapes
 
 import 'dart:convert' as _i19;
@@ -39,205 +38,185 @@ String renderCategory(_i1.CategoryTemplateData context0) {
 
 <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
   <h1><span class="kind-category">''');
-    buffer.writeEscaped(context1.name.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('''</h1>
+  buffer.writeEscaped(context1.name.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('''</h1>
   ''');
-    buffer.write(_renderCategory_partial_documentation_1(context1, context0));
+  buffer.write(_renderCategory_partial_documentation_1(context1, context0));
+  buffer.writeln();
+  if (context1.hasPublicLibraries == true) {
     buffer.writeln();
-    if (context1.hasPublicLibraries == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="libraries">
     <h2>Libraries</h2>
 
     <dl>''');
-      var context2 = context1.publicLibrariesSorted;
-      if (context2 != null) {
-        for (var context3 in context2) {
-          buffer.write('\n      ');
-          buffer.write(
-              _renderCategory_partial_library_2(context3, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context2 = context1.publicLibrariesSorted;
+    for (var context3 in context2) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_library_2(context3, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context1.hasPublicClasses == true) {
     buffer.writeln();
-    if (context1.hasPublicClasses == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="classes">
     <h2>Classes</h2>
 
     <dl>''');
-      var context4 = context1.publicClassesSorted;
-      if (context4 != null) {
-        for (var context5 in context4) {
-          buffer.write('\n      ');
-          buffer.write(_renderCategory_partial_container_3(
-              context5, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context4 = context1.publicClassesSorted;
+    for (var context5 in context4) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_container_3(context5, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context1.hasPublicMixins == true) {
     buffer.writeln();
-    if (context1.hasPublicMixins == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="mixins">
     <h2>Mixins</h2>
 
     <dl>''');
-      var context6 = context1.publicMixinsSorted;
-      if (context6 != null) {
-        for (var context7 in context6) {
-          buffer.write('\n      ');
-          buffer.write(_renderCategory_partial_container_3(
-              context7, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context6 = context1.publicMixinsSorted;
+    for (var context7 in context6) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_container_3(context7, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context1.hasPublicConstants == true) {
     buffer.writeln();
-    if (context1.hasPublicConstants == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="constants">
     <h2>Constants</h2>
 
     <dl class="properties">''');
-      var context8 = context1.publicConstantsSorted;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.write('\n      ');
-          buffer.write(
-              _renderCategory_partial_constant_4(context9, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context8 = context1.publicConstantsSorted;
+    for (var context9 in context8) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_constant_4(context9, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context1.hasPublicProperties == true) {
     buffer.writeln();
-    if (context1.hasPublicProperties == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="properties">
     <h2>Properties</h2>
 
     <dl class="properties">''');
-      var context10 = context1.publicPropertiesSorted;
-      if (context10 != null) {
-        for (var context11 in context10) {
-          buffer.write('\n      ');
-          buffer.write(_renderCategory_partial_property_5(
-              context11, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context10 = context1.publicPropertiesSorted;
+    for (var context11 in context10) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_property_5(context11, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context1.hasPublicFunctions == true) {
     buffer.writeln();
-    if (context1.hasPublicFunctions == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="functions">
     <h2>Functions</h2>
 
     <dl class="callables">''');
-      var context12 = context1.publicFunctionsSorted;
-      if (context12 != null) {
-        for (var context13 in context12) {
-          buffer.write('\n      ');
-          buffer.write(_renderCategory_partial_callable_6(
-              context13, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context12 = context1.publicFunctionsSorted;
+    for (var context13 in context12) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_callable_6(context13, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context1.hasPublicEnums == true) {
     buffer.writeln();
-    if (context1.hasPublicEnums == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="enums">
     <h2>Enums</h2>
 
     <dl>''');
-      var context14 = context1.publicEnumsSorted;
-      if (context14 != null) {
-        for (var context15 in context14) {
-          buffer.write('\n      ');
-          buffer.write(_renderCategory_partial_container_3(
-              context15, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context14 = context1.publicEnumsSorted;
+    for (var context15 in context14) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_container_3(context15, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context1.hasPublicTypedefs == true) {
     buffer.writeln();
-    if (context1.hasPublicTypedefs == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="typedefs">
     <h2>Typedefs</h2>
 
     <dl class="callables">''');
-      var context16 = context1.publicTypedefsSorted;
-      if (context16 != null) {
-        for (var context17 in context16) {
-          buffer.write('\n      ');
-          buffer.write(
-              _renderCategory_partial_typedef_7(context17, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context16 = context1.publicTypedefsSorted;
+    for (var context17 in context16) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_typedef_7(context17, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context1.hasPublicExceptions == true) {
     buffer.writeln();
-    if (context1.hasPublicExceptions == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
   <section class="summary offset-anchor" id="exceptions">
     <h2>Exceptions / Errors</h2>
 
     <dl>''');
-      var context18 = context1.publicExceptionsSorted;
-      if (context18 != null) {
-        for (var context19 in context18) {
-          buffer.write('\n      ');
-          buffer.write(_renderCategory_partial_container_3(
-              context19, context1, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context18 = context1.publicExceptionsSorted;
+    for (var context19 in context18) {
+      buffer.write('\n      ');
+      buffer.write(
+          _renderCategory_partial_container_3(context19, context1, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
     </dl>
   </section>''');
-    }
   }
   buffer.writeln();
   buffer.write('''
@@ -250,9 +229,9 @@ String renderCategory(_i1.CategoryTemplateData context0) {
   buffer.writeln();
   buffer.write('''
   <h5><span class="package-name">''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write('''</span> <span class="package-kind">''');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</span></h5>
   ''');
   buffer.write(_renderCategory_partial_packages_9(context0));
@@ -307,7 +286,7 @@ String _renderCategory_partial_head_0(_i1.CategoryTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -315,14 +294,12 @@ String _renderCategory_partial_head_0(_i1.CategoryTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -371,33 +348,29 @@ String _renderCategory_partial_head_0(_i1.CategoryTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -410,7 +383,7 @@ String _renderCategory_partial_head_0(_i1.CategoryTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -440,7 +413,7 @@ String _renderCategory_partial_documentation_1(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -466,7 +439,7 @@ String _renderCategory_partial_library_2(_i3.Library context2,
 </dt>
 <dd>''');
   if (context2.isDocumented == true) {
-    buffer.write(context2.oneLineDoc.toString());
+    buffer.write(context2.oneLineDoc?.toString());
     buffer.write(' ');
     buffer.write(context2.extendedDocLink.toString());
   }
@@ -485,11 +458,9 @@ String __renderCategory_partial_library_2_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -518,7 +489,7 @@ String _renderCategory_partial_container_3(_i4.Container context2,
 </dt>
 <dd>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.writeln();
@@ -536,11 +507,9 @@ String __renderCategory_partial_container_3_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -572,7 +541,7 @@ String _renderCategory_partial_constant_4(_i5.TopLevelVariable context2,
 </dt>
 <dd>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -598,11 +567,9 @@ String __renderCategory_partial_constant_4_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -654,7 +621,7 @@ String _renderCategory_partial_property_5(_i5.TopLevelVariable context2,
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -675,11 +642,9 @@ String __renderCategory_partial_property_5_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -721,7 +686,7 @@ String _renderCategory_partial_callable_6(_i6.ModelFunctionTyped context2,
   buffer.write('''</span>''');
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''<span class="signature">(<wbr>''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''')
     <span class="returntype parameter">&#8594; ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
@@ -739,7 +704,7 @@ String _renderCategory_partial_callable_6(_i6.ModelFunctionTyped context2,
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -760,11 +725,9 @@ String __renderCategory_partial_callable_6_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -792,51 +755,49 @@ String _renderCategory_partial_typedef_7(_i7.Typedef context2,
   final buffer = StringBuffer();
   if (context2.isCallable == true) {
     var context3 = context2.asCallable;
-    if (context3 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <dt id="''');
-      buffer.writeEscaped(context3.htmlId.toString());
-      buffer.write('''" class="callable''');
-      if (context3.isInherited == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''">
+    buffer.writeEscaped(context3.htmlId.toString());
+    buffer.write('''" class="callable''');
+    if (context3.isInherited == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''">
     <span class="name''');
-      if (context3.isDeprecated == true) {
-        buffer.write(''' deprecated''');
-      }
-      buffer.write('''">''');
-      buffer.write(context3.linkedName.toString());
-      buffer.write('''</span>''');
-      buffer.write(context3.linkedGenericParameters.toString());
-      buffer.write('''<span class="signature">
+    if (context3.isDeprecated == true) {
+      buffer.write(''' deprecated''');
+    }
+    buffer.write('''">''');
+    buffer.write(context3.linkedName.toString());
+    buffer.write('''</span>''');
+    buffer.write(context3.linkedGenericParameters.toString());
+    buffer.write('''<span class="signature">
       <span class="returntype parameter">= ''');
-      buffer.write(context3.modelType.linkedName.toString());
-      buffer.write('''</span>
+    buffer.write(context3.modelType.linkedName.toString());
+    buffer.write('''</span>
     </span>
     ''');
-      buffer.write(__renderCategory_partial_typedef_7_partial_categorization_0(
-          context3, context2, context1, context0));
-      buffer.writeln();
-      buffer.write('''
+    buffer.write(__renderCategory_partial_typedef_7_partial_categorization_0(
+        context3, context2, context1, context0));
+    buffer.writeln();
+    buffer.write('''
   </dt>
   <dd''');
-      if (context3.isInherited == true) {
-        buffer.write(''' class="inherited"''');
-      }
-      buffer.write('''>
+    if (context3.isInherited == true) {
+      buffer.write(''' class="inherited"''');
+    }
+    buffer.write('''>
     ''');
-      buffer.write(context3.oneLineDoc.toString());
-      buffer.write(' ');
-      buffer.write(context3.extendedDocLink.toString());
-      buffer.write('\n    ');
-      buffer.write(__renderCategory_partial_typedef_7_partial_features_1(
-          context3, context2, context1, context0));
-      buffer.writeln();
-      buffer.write('''
+    buffer.write(context3.oneLineDoc?.toString());
+    buffer.write(' ');
+    buffer.write(context3.extendedDocLink.toString());
+    buffer.write('\n    ');
+    buffer.write(__renderCategory_partial_typedef_7_partial_features_1(
+        context3, context2, context1, context0));
+    buffer.writeln();
+    buffer.write('''
   </dd>''');
-    }
   }
   if (context2.isCallable != true) {
     buffer.write('\n  ');
@@ -856,11 +817,9 @@ String __renderCategory_partial_typedef_7_partial_categorization_0(
   final buffer = StringBuffer();
   if (context3.hasCategoryNames == true) {
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.write('\n    ');
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.write('\n    ');
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -922,7 +881,7 @@ String __renderCategory_partial_typedef_7_partial_type_2(_i7.Typedef context2,
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -945,11 +904,9 @@ String
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -983,33 +940,29 @@ String _renderCategory_partial_search_sidebar_8(
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -1022,7 +975,7 @@ String _renderCategory_partial_search_sidebar_8(
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -1040,67 +993,57 @@ String _renderCategory_partial_packages_9(_i1.CategoryTemplateData context0) {
   final buffer = StringBuffer();
   buffer.write('''<ol>''');
   var context1 = context0.localPackages;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      if (context2.isFirstPackage == true) {
-        if (context2.hasDocumentedCategories == true) {
+  for (var context2 in context1) {
+    if (context2.isFirstPackage == true) {
+      if (context2.hasDocumentedCategories == true) {
+        buffer.writeln();
+        buffer.write('''
+      <li class="section-title">Topics</li>''');
+        var context3 = context2.documentedCategoriesSorted;
+        for (var context4 in context3) {
           buffer.writeln();
           buffer.write('''
-      <li class="section-title">Topics</li>''');
-          var context3 = context2.documentedCategoriesSorted;
-          if (context3 != null) {
-            for (var context4 in context3) {
-              buffer.writeln();
-              buffer.write('''
         <li>''');
-              buffer.write(context4.linkedName.toString());
-              buffer.write('''</li>''');
-            }
-          }
+          buffer.write(context4.linkedName.toString());
+          buffer.write('''</li>''');
         }
-        buffer.writeln();
-        buffer.write('''
-      <li class="section-title">Libraries</li>''');
       }
-      if (context2.isFirstPackage != true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.writeln();
+      buffer.write('''
+      <li class="section-title">Libraries</li>''');
+    }
+    if (context2.isFirstPackage != true) {
+      buffer.writeln();
+      buffer.write('''
       <li class="section-title">''');
-        buffer.writeEscaped(context2.name.toString());
-        buffer.write('''</li>''');
-      }
-      var context5 = context2.defaultCategory;
-      if (context5 != null) {
-        var context6 = context5.publicLibrariesSorted;
-        if (context6 != null) {
-          for (var context7 in context6) {
-            buffer.writeln();
-            buffer.write('''
+      buffer.writeEscaped(context2.name.toString());
+      buffer.write('''</li>''');
+    }
+    var context5 = context2.defaultCategory;
+    if (context5 != null) {
+      var context6 = context5.publicLibrariesSorted;
+      for (var context7 in context6) {
+        buffer.writeln();
+        buffer.write('''
       <li>''');
-            buffer.write(context7.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context7.linkedName.toString());
+        buffer.write('''</li>''');
       }
-      var context8 = context2.categoriesWithPublicLibraries;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.writeln();
-          buffer.write('''
+    }
+    var context8 = context2.categoriesWithPublicLibraries;
+    for (var context9 in context8) {
+      buffer.writeln();
+      buffer.write('''
       <li class="section-subtitle">''');
-          buffer.writeEscaped(context9.name.toString());
-          buffer.write('''</li>''');
-          var context10 = context9.publicLibrariesSorted;
-          if (context10 != null) {
-            for (var context11 in context10) {
-              buffer.writeln();
-              buffer.write('''
+      buffer.writeEscaped(context9.name.toString());
+      buffer.write('''</li>''');
+      var context10 = context9.publicLibrariesSorted;
+      for (var context11 in context10) {
+        buffer.writeln();
+        buffer.write('''
         <li class="section-subitem">''');
-              buffer.write(context11.linkedName.toString());
-              buffer.write('''</li>''');
-            }
-          }
-        }
+        buffer.write(context11.linkedName.toString());
+        buffer.write('''</li>''');
       }
     }
   }
@@ -1117,218 +1060,164 @@ String _renderCategory_partial_sidebar_for_category_10(
   final buffer = StringBuffer();
   buffer.write('''<ol>''');
   var context1 = context0.self;
-  if (context1 != null) {
-    if (context1.hasPublicLibraries == true) {
+  if (context1.hasPublicLibraries == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#libraries">Libraries</a></li>''');
+    var context2 = context0.self;
+    var context3 = context2.publicLibrariesSorted;
+    for (var context4 in context3) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#libraries">Libraries</a></li>''');
-      var context2 = context0.self;
-      if (context2 != null) {
-        var context3 = context2.publicLibrariesSorted;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context4.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context4.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
   var context5 = context0.self;
-  if (context5 != null) {
-    if (context5.hasPublicMixins == true) {
+  if (context5.hasPublicMixins == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#mixins">Mixins</a></li>''');
+    var context6 = context0.self;
+    var context7 = context6.publicMixinsSorted;
+    for (var context8 in context7) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#mixins">Mixins</a></li>''');
-      var context6 = context0.self;
-      if (context6 != null) {
-        var context7 = context6.publicMixinsSorted;
-        if (context7 != null) {
-          for (var context8 in context7) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context8.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context8.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
   var context9 = context0.self;
-  if (context9 != null) {
-    if (context9.hasPublicClasses == true) {
+  if (context9.hasPublicClasses == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#classes">Classes</a></li>''');
+    var context10 = context0.self;
+    var context11 = context10.publicClassesSorted;
+    for (var context12 in context11) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#classes">Classes</a></li>''');
-      var context10 = context0.self;
-      if (context10 != null) {
-        var context11 = context10.publicClassesSorted;
-        if (context11 != null) {
-          for (var context12 in context11) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context12.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context12.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
   var context13 = context0.self;
-  if (context13 != null) {
-    if (context13.hasPublicConstants == true) {
+  if (context13.hasPublicConstants == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#constants">Constants</a></li>''');
+    var context14 = context0.self;
+    var context15 = context14.publicConstantsSorted;
+    for (var context16 in context15) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#constants">Constants</a></li>''');
-      var context14 = context0.self;
-      if (context14 != null) {
-        var context15 = context14.publicConstantsSorted;
-        if (context15 != null) {
-          for (var context16 in context15) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context16.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context16.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
   var context17 = context0.self;
-  if (context17 != null) {
-    if (context17.hasPublicProperties == true) {
+  if (context17.hasPublicProperties == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#properties">Properties</a></li>''');
+    var context18 = context0.self;
+    var context19 = context18.publicPropertiesSorted;
+    for (var context20 in context19) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#properties">Properties</a></li>''');
-      var context18 = context0.self;
-      if (context18 != null) {
-        var context19 = context18.publicPropertiesSorted;
-        if (context19 != null) {
-          for (var context20 in context19) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context20.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context20.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
   var context21 = context0.self;
-  if (context21 != null) {
-    if (context21.hasPublicFunctions == true) {
+  if (context21.hasPublicFunctions == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#functions">Functions</a></li>''');
+    var context22 = context0.self;
+    var context23 = context22.publicFunctionsSorted;
+    for (var context24 in context23) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#functions">Functions</a></li>''');
-      var context22 = context0.self;
-      if (context22 != null) {
-        var context23 = context22.publicFunctionsSorted;
-        if (context23 != null) {
-          for (var context24 in context23) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context24.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context24.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
   var context25 = context0.self;
-  if (context25 != null) {
-    if (context25.hasPublicEnums == true) {
+  if (context25.hasPublicEnums == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#enums">Enums</a></li>''');
+    var context26 = context0.self;
+    var context27 = context26.publicEnumsSorted;
+    for (var context28 in context27) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#enums">Enums</a></li>''');
-      var context26 = context0.self;
-      if (context26 != null) {
-        var context27 = context26.publicEnumsSorted;
-        if (context27 != null) {
-          for (var context28 in context27) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context28.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context28.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
   var context29 = context0.self;
-  if (context29 != null) {
-    if (context29.hasPublicTypedefs == true) {
+  if (context29.hasPublicTypedefs == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#typedefs">Typedefs</a></li>''');
+    var context30 = context0.self;
+    var context31 = context30.publicTypedefsSorted;
+    for (var context32 in context31) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#typedefs">Typedefs</a></li>''');
-      var context30 = context0.self;
-      if (context30 != null) {
-        var context31 = context30.publicTypedefsSorted;
-        if (context31 != null) {
-          for (var context32 in context31) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context32.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context32.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
   var context33 = context0.self;
-  if (context33 != null) {
-    if (context33.hasPublicExceptions == true) {
+  if (context33.hasPublicExceptions == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context0.self.href?.toString());
+    buffer.write('''#exceptions">Exceptions</a></li>''');
+    var context34 = context0.self;
+    var context35 = context34.publicExceptionsSorted;
+    for (var context36 in context35) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context0.self.href.toString());
-      buffer.write('''#exceptions">Exceptions</a></li>''');
-      var context34 = context0.self;
-      if (context34 != null) {
-        var context35 = context34.publicExceptionsSorted;
-        if (context35 != null) {
-          for (var context36 in context35) {
-            buffer.writeln();
-            buffer.write('''
   <li>''');
-            buffer.write(context36.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
-      }
+      buffer.write(context36.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
@@ -1397,346 +1286,316 @@ String renderClass(_i1.ClassTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderClass_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-class">''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderClass_partial_feature_set_2(context1, context0));
-    buffer.write(' ');
-    buffer.write(_renderClass_partial_categorization_3(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderClass_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-class">''');
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderClass_partial_feature_set_2(context1, context0));
+  buffer.write(' ');
+  buffer.write(_renderClass_partial_categorization_3(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.clazz;
-  if (context2 != null) {
-    buffer.write('\n    ');
-    buffer.write(_renderClass_partial_documentation_4(context2, context0));
+  buffer.write('\n    ');
+  buffer.write(_renderClass_partial_documentation_4(context2, context0));
+  buffer.writeln();
+  if (context2.hasModifiers == true) {
     buffer.writeln();
-    if (context2.hasModifiers == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section>
       <dl class="dl-horizontal">''');
-      if (context2.hasPublicSuperChainReversed == true) {
-        buffer.writeln();
-        buffer.write('''
+    if (context2.hasPublicSuperChainReversed == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Inheritance</dt>
         <dd><ul class="gt-separated dark clazz-relationships">
           <li>''');
-        buffer.write(context0.linkedObjectType.toString());
-        buffer.write('''</li>''');
-        var context3 = context2.publicSuperChainReversed;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context4.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      buffer.write(context0.linkedObjectType.toString());
+      buffer.write('''</li>''');
+      var context3 = context2.publicSuperChainReversed;
+      for (var context4 in context3) {
         buffer.writeln();
         buffer.write('''
           <li>''');
-        buffer.write(context2.name.toString());
-        buffer.write('''</li>
-        </ul></dd>''');
+        buffer.write(context4.linkedName.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
-      if (context2.hasPublicInterfaces == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
+          <li>''');
+      buffer.write(context2.name.toString());
+      buffer.write('''</li>
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    if (context2.hasPublicInterfaces == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Implemented types</dt>
         <dd>
           <ul class="comma-separated clazz-relationships">''');
-        var context5 = context2.publicInterfaces;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.writeln();
-            buffer.write('''
-            <li>''');
-            buffer.write(context6.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context5 = context2.publicInterfaces;
+      for (var context6 in context5) {
         buffer.writeln();
         buffer.write('''
+            <li>''');
+        buffer.write(context6.linkedName.toString());
+        buffer.write('''</li>''');
+      }
+      buffer.writeln();
+      buffer.write('''
           </ul>
         </dd>''');
-      }
+    }
+    buffer.writeln();
+    if (context2.hasPublicMixedInTypes == true) {
       buffer.writeln();
-      if (context2.hasPublicMixedInTypes == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
         <dt>Mixed in types</dt>
         <dd><ul class="comma-separated clazz-relationships">''');
-        var context7 = context2.publicMixedInTypes;
-        if (context7 != null) {
-          for (var context8 in context7) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context8.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context7 = context2.publicMixedInTypes;
+      for (var context8 in context7) {
         buffer.writeln();
         buffer.write('''
-        </ul></dd>''');
+          <li>''');
+        buffer.write(context8.linkedName.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
-      if (context2.hasPublicImplementors == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    if (context2.hasPublicImplementors == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Implementers</dt>
         <dd><ul class="comma-separated clazz-relationships">''');
-        var context9 = context2.publicImplementorsSorted;
-        if (context9 != null) {
-          for (var context10 in context9) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context10.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context9 = context2.publicImplementorsSorted;
+      for (var context10 in context9) {
         buffer.writeln();
         buffer.write('''
-        </ul></dd>''');
+          <li>''');
+        buffer.write(context10.linkedName.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
-      if (context2.hasPotentiallyApplicableExtensions == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    if (context2.hasPotentiallyApplicableExtensions == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Available Extensions</dt>
         <dd><ul class="comma-separated clazz-relationships">''');
-        var context11 = context2.potentiallyApplicableExtensionsSorted;
-        if (context11 != null) {
-          for (var context12 in context11) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context12.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context11 = context2.potentiallyApplicableExtensionsSorted;
+      for (var context12 in context11) {
         buffer.writeln();
         buffer.write('''
-        </ul></dd>''');
+          <li>''');
+        buffer.write(context12.linkedName.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
-      if (context2.hasAnnotations == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    if (context2.hasAnnotations == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Annotations</dt>
         <dd><ul class="annotation-list clazz-relationships">''');
-        var context13 = context2.annotations;
-        if (context13 != null) {
-          for (var context14 in context13) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context14.linkedNameWithParameters.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context13 = context2.annotations;
+      for (var context14 in context13) {
         buffer.writeln();
         buffer.write('''
-        </ul></dd>''');
+          <li>''');
+        buffer.write(context14.linkedNameWithParameters.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
       buffer.write('''
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstructors == true) {
     buffer.writeln();
-    if (context2.hasPublicConstructors == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="constructors">
       <h2>Constructors</h2>
 
       <dl class="constructor-summary-list">''');
-      var context15 = context2.publicConstructorsSorted;
-      if (context15 != null) {
-        for (var context16 in context15) {
-          buffer.writeln();
-          buffer.write('''
+    var context15 = context2.publicConstructorsSorted;
+    for (var context16 in context15) {
+      buffer.writeln();
+      buffer.write('''
         <dt id="''');
-          buffer.writeEscaped(context16.htmlId.toString());
-          buffer.write('''" class="callable">
+      buffer.writeEscaped(context16.htmlId.toString());
+      buffer.write('''" class="callable">
           <span class="name">''');
-          buffer.write(context16.linkedName.toString());
-          buffer.write('''</span><span class="signature">(''');
-          buffer.write(context16.linkedParams.toString());
-          buffer.write(''')</span>
+      buffer.write(context16.linkedName.toString());
+      buffer.write('''</span><span class="signature">(''');
+      buffer.write(context16.linkedParams.toString());
+      buffer.write(''')</span>
         </dt>
         <dd>
           ''');
-          buffer.write(context16.oneLineDoc.toString());
-          buffer.write(' ');
-          buffer.write(context16.extendedDocLink.toString());
-          if (context16.isConst == true) {
-            buffer.writeln();
-            buffer.write('''
+      buffer.write(context16.oneLineDoc?.toString());
+      buffer.write(' ');
+      buffer.write(context16.extendedDocLink.toString());
+      if (context16.isConst == true) {
+        buffer.writeln();
+        buffer.write('''
           <div class="constructor-modifier features">const</div>''');
-          }
-          if (context16.isFactory == true) {
-            buffer.writeln();
-            buffer.write('''
+      }
+      if (context16.isFactory == true) {
+        buffer.writeln();
+        buffer.write('''
           <div class="constructor-modifier features">factory</div>''');
-          }
-          buffer.writeln();
-          buffer.write('''
-        </dd>''');
-        }
       }
       buffer.writeln();
       buffer.write('''
+        </dd>''');
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceFields == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceFields == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="instance-properties">
+    if (context2.publicInheritedInstanceFields == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="instance-properties">
       <h2>Properties</h2>
 
       <dl class="properties">''');
-      var context17 = context2.publicInstanceFieldsSorted;
-      if (context17 != null) {
-        for (var context18 in context17) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderClass_partial_property_5(context18, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context17 = context2.publicInstanceFieldsSorted;
+    for (var context18 in context17) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderClass_partial_property_5(context18, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceMethods == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="instance-methods">
+    if (context2.publicInheritedInstanceMethods == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="instance-methods">
       <h2>Methods</h2>
       <dl class="callables">''');
-      var context19 = context2.publicInstanceMethodsSorted;
-      if (context19 != null) {
-        for (var context20 in context19) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderClass_partial_callable_6(context20, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context19 = context2.publicInstanceMethodsSorted;
+    for (var context20 in context19) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderClass_partial_callable_6(context20, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceOperators == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceOperators == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceOperators == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="operators">
+    if (context2.publicInheritedInstanceOperators == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="operators">
       <h2>Operators</h2>
       <dl class="callables">''');
-      var context21 = context2.publicInstanceOperatorsSorted;
-      if (context21 != null) {
-        for (var context22 in context21) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderClass_partial_callable_6(context22, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context21 = context2.publicInstanceOperatorsSorted;
+    for (var context22 in context21) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderClass_partial_callable_6(context22, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicVariableStaticFields == true) {
     buffer.writeln();
-    if (context2.hasPublicVariableStaticFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="static-properties">
       <h2>Static Properties</h2>
 
       <dl class="properties">''');
-      var context23 = context2.publicVariableStaticFieldsSorted;
-      if (context23 != null) {
-        for (var context24 in context23) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderClass_partial_property_5(context24, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context23 = context2.publicVariableStaticFieldsSorted;
+    for (var context24 in context23) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderClass_partial_property_5(context24, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicStaticMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicStaticMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="static-methods">
       <h2>Static Methods</h2>
       <dl class="callables">''');
-      var context25 = context2.publicStaticMethodsSorted;
-      if (context25 != null) {
-        for (var context26 in context25) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderClass_partial_callable_6(context26, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context25 = context2.publicStaticMethodsSorted;
+    for (var context26 in context25) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderClass_partial_callable_6(context26, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstantFields == true) {
     buffer.writeln();
-    if (context2.hasPublicConstantFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="constants">
       <h2>Constants</h2>
 
       <dl class="properties">''');
-      var context27 = context2.publicConstantFieldsSorted;
-      if (context27 != null) {
-        for (var context28 in context27) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderClass_partial_constant_7(context28, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context27 = context2.publicConstantFieldsSorted;
+    for (var context28 in context27) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderClass_partial_constant_7(context28, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   buffer.write('''
@@ -1749,9 +1608,9 @@ String renderClass(_i1.ClassTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForLibrary.toString());
@@ -1801,7 +1660,7 @@ String _renderClass_partial_head_0(_i1.ClassTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -1809,14 +1668,12 @@ String _renderClass_partial_head_0(_i1.ClassTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -1865,33 +1722,29 @@ String _renderClass_partial_head_0(_i1.ClassTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -1904,7 +1757,7 @@ String _renderClass_partial_head_0(_i1.ClassTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -1946,11 +1799,9 @@ String _renderClass_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -1963,11 +1814,9 @@ String _renderClass_partial_categorization_3(
   final buffer = StringBuffer();
   if (context1.hasCategoryNames == true) {
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1983,7 +1832,7 @@ String _renderClass_partial_documentation_4(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -2022,7 +1871,7 @@ String _renderClass_partial_property_5(
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -2041,11 +1890,9 @@ String __renderClass_partial_property_5_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2085,7 +1932,7 @@ String _renderClass_partial_callable_6(
   buffer.write('''</span>''');
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''<span class="signature">(<wbr>''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''')
     <span class="returntype parameter">&#8594; ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
@@ -2103,7 +1950,7 @@ String _renderClass_partial_callable_6(
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -2122,11 +1969,9 @@ String __renderClass_partial_callable_6_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2171,7 +2016,7 @@ String _renderClass_partial_constant_7(
 </dt>
 <dd>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -2195,11 +2040,9 @@ String __renderClass_partial_constant_7_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2230,33 +2073,29 @@ String _renderClass_partial_search_sidebar_8(_i1.ClassTemplateData context0) {
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -2269,7 +2108,7 @@ String _renderClass_partial_search_sidebar_8(_i1.ClassTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -2341,70 +2180,63 @@ String renderConstructor(_i1.ConstructorTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderConstructor_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-constructor">''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderConstructor_partial_feature_set_2(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderConstructor_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-constructor">''');
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderConstructor_partial_feature_set_2(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.constructor;
-  if (context2 != null) {
+  buffer.writeln();
+  buffer.write('''
+    <section class="multi-line-signature">''');
+  if (context2.hasAnnotations == true) {
     buffer.writeln();
     buffer.write('''
-    <section class="multi-line-signature">''');
-    if (context2.hasAnnotations == true) {
-      buffer.writeln();
-      buffer.write('''
       <div>
         <ol class="annotation-list">''');
-      var context3 = context2.annotations;
-      if (context3 != null) {
-        for (var context4 in context3) {
-          buffer.writeln();
-          buffer.write('''
-          <li>''');
-          buffer.write(context4.linkedNameWithParameters.toString());
-          buffer.write('''</li>''');
-        }
-      }
+    var context3 = context2.annotations;
+    for (var context4 in context3) {
       buffer.writeln();
       buffer.write('''
-        </ol>
-      </div>''');
-    }
-    if (context2.isConst == true) {
-      buffer.write('''const''');
+          <li>''');
+      buffer.write(context4.linkedNameWithParameters.toString());
+      buffer.write('''</li>''');
     }
     buffer.writeln();
     buffer.write('''
+        </ol>
+      </div>''');
+  }
+  if (context2.isConst == true) {
+    buffer.write('''const''');
+  }
+  buffer.writeln();
+  buffer.write('''
       <span class="name ''');
-    if (context2.isDeprecated == true) {
-      buffer.write('''deprecated''');
-    }
-    buffer.write('''">''');
-    buffer.write(context2.nameWithGenerics.toString());
-    buffer.write('''</span>(<wbr>''');
-    if (context2.hasParameters == true) {
-      buffer.write(context2.linkedParamsLines.toString());
-    }
-    buffer.write(''')
+  if (context2.isDeprecated == true) {
+    buffer.write('''deprecated''');
+  }
+  buffer.write('''">''');
+  buffer.write(context2.nameWithGenerics.toString());
+  buffer.write('''</span>(<wbr>''');
+  if (context2.hasParameters == true) {
+    buffer.write(context2.linkedParamsLines.toString());
+  }
+  buffer.write(''')
     </section>
 
     ''');
-    buffer
-        .write(_renderConstructor_partial_documentation_3(context2, context0));
-    buffer.write('\n\n    ');
-    buffer.write(_renderConstructor_partial_source_code_4(context2, context0));
-    buffer.writeln();
-  }
+  buffer.write(_renderConstructor_partial_documentation_3(context2, context0));
+  buffer.write('\n\n    ');
+  buffer.write(_renderConstructor_partial_source_code_4(context2, context0));
+  buffer.writeln();
   buffer.writeln();
   buffer.write('''
   </div> <!-- /.main-content -->
@@ -2415,9 +2247,9 @@ String renderConstructor(_i1.ConstructorTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForContainer.toString());
@@ -2463,7 +2295,7 @@ String _renderConstructor_partial_head_0(_i1.ConstructorTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -2471,14 +2303,12 @@ String _renderConstructor_partial_head_0(_i1.ConstructorTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -2526,34 +2356,30 @@ String _renderConstructor_partial_head_0(_i1.ConstructorTemplateData context0) {
 <header id="title">
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
-  var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  var context3 = context0.navLinks;
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -2566,7 +2392,7 @@ String _renderConstructor_partial_head_0(_i1.ConstructorTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -2608,11 +2434,9 @@ String _renderConstructor_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -2628,7 +2452,7 @@ String _renderConstructor_partial_documentation_3(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -2667,33 +2491,29 @@ String _renderConstructor_partial_search_sidebar_5(
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -2706,7 +2526,7 @@ String _renderConstructor_partial_search_sidebar_5(
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -2779,217 +2599,197 @@ String renderEnum(_i1.EnumTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderEnum_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-enum">''');
-    buffer.write(context1.name.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderEnum_partial_feature_set_2(context1, context0));
-    buffer.write(' ');
-    buffer.write(_renderEnum_partial_categorization_3(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderEnum_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-enum">''');
+  buffer.write(context1.name.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderEnum_partial_feature_set_2(context1, context0));
+  buffer.write(' ');
+  buffer.write(_renderEnum_partial_categorization_3(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.eNum;
-  if (context2 != null) {
-    buffer.write('\n    ');
-    buffer.write(_renderEnum_partial_documentation_4(context2, context0));
+  buffer.write('\n    ');
+  buffer.write(_renderEnum_partial_documentation_4(context2, context0));
+  buffer.writeln();
+  if (context2.hasModifiers == true) {
     buffer.writeln();
-    if (context2.hasModifiers == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section>
       <dl class="dl-horizontal">''');
-      if (context2.hasPublicSuperChainReversed == true) {
-        buffer.writeln();
-        buffer.write('''
+    if (context2.hasPublicSuperChainReversed == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Inheritance</dt>
         <dd><ul class="gt-separated dark eNum-relationships">
           <li>''');
-        buffer.write(context0.linkedObjectType.toString());
-        buffer.write('''</li>''');
-        var context3 = context2.publicSuperChainReversed;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context4.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      buffer.write(context0.linkedObjectType.toString());
+      buffer.write('''</li>''');
+      var context3 = context2.publicSuperChainReversed;
+      for (var context4 in context3) {
         buffer.writeln();
         buffer.write('''
           <li>''');
-        buffer.write(context2.name.toString());
-        buffer.write('''</li>
-        </ul></dd>''');
+        buffer.write(context4.linkedName.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
-      if (context2.hasAnnotations == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
+          <li>''');
+      buffer.write(context2.name.toString());
+      buffer.write('''</li>
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    if (context2.hasAnnotations == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Annotations</dt>
         <dd><ul class="annotation-list eNum-relationships">''');
-        var context5 = context2.annotations;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context6.linkedNameWithParameters.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context5 = context2.annotations;
+      for (var context6 in context5) {
         buffer.writeln();
         buffer.write('''
-        </ul></dd>''');
+          <li>''');
+        buffer.write(context6.linkedNameWithParameters.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
       buffer.write('''
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstantFields == true) {
     buffer.writeln();
-    if (context2.hasPublicConstantFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="constants">
       <h2>Constants</h2>
 
       <dl class="properties">''');
-      var context7 = context2.publicConstantFieldsSorted;
-      if (context7 != null) {
-        for (var context8 in context7) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderEnum_partial_constant_5(context8, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context7 = context2.publicConstantFieldsSorted;
+    for (var context8 in context7) {
+      buffer.write('\n        ');
+      buffer
+          .write(_renderEnum_partial_constant_5(context8, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceFields == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceFields == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="instance-properties">
+    if (context2.publicInheritedInstanceFields == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="instance-properties">
       <h2>Properties</h2>
 
       <dl class="properties">''');
-      var context9 = context2.publicInstanceFieldsSorted;
-      if (context9 != null) {
-        for (var context10 in context9) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderEnum_partial_property_6(context10, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context9 = context2.publicInstanceFieldsSorted;
+    for (var context10 in context9) {
+      buffer.write('\n        ');
+      buffer
+          .write(_renderEnum_partial_property_6(context10, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceMethods == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="instance-methods">
+    if (context2.publicInheritedInstanceMethods == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="instance-methods">
       <h2>Methods</h2>
       <dl class="callables">''');
-      var context11 = context2.publicInstanceMethodsSorted;
-      if (context11 != null) {
-        for (var context12 in context11) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderEnum_partial_callable_7(context12, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context11 = context2.publicInstanceMethodsSorted;
+    for (var context12 in context11) {
+      buffer.write('\n        ');
+      buffer
+          .write(_renderEnum_partial_callable_7(context12, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceOperators == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceOperators == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceOperators == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="operators">
+    if (context2.publicInheritedInstanceOperators == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="operators">
       <h2>Operators</h2>
       <dl class="callables">''');
-      var context13 = context2.publicInstanceOperatorsSorted;
-      if (context13 != null) {
-        for (var context14 in context13) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderEnum_partial_callable_7(context14, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context13 = context2.publicInstanceOperatorsSorted;
+    for (var context14 in context13) {
+      buffer.write('\n        ');
+      buffer
+          .write(_renderEnum_partial_callable_7(context14, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicVariableStaticFields == true) {
     buffer.writeln();
-    if (context2.hasPublicVariableStaticFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="static-properties">
       <h2>Static Properties</h2>
 
       <dl class="properties">''');
-      var context15 = context2.publicVariableStaticFieldsSorted;
-      if (context15 != null) {
-        for (var context16 in context15) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderEnum_partial_property_6(context16, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context15 = context2.publicVariableStaticFieldsSorted;
+    for (var context16 in context15) {
+      buffer.write('\n        ');
+      buffer
+          .write(_renderEnum_partial_property_6(context16, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicStaticMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicStaticMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="static-methods">
       <h2>Static Methods</h2>
       <dl class="callables">''');
-      var context17 = context2.publicStaticMethodsSorted;
-      if (context17 != null) {
-        for (var context18 in context17) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderEnum_partial_callable_7(context18, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context17 = context2.publicStaticMethodsSorted;
+    for (var context18 in context17) {
+      buffer.write('\n        ');
+      buffer
+          .write(_renderEnum_partial_callable_7(context18, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   buffer.write('''
@@ -3001,9 +2801,9 @@ String renderEnum(_i1.EnumTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForLibrary.toString());
@@ -3053,7 +2853,7 @@ String _renderEnum_partial_head_0(_i1.EnumTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -3061,14 +2861,12 @@ String _renderEnum_partial_head_0(_i1.EnumTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -3117,33 +2915,29 @@ String _renderEnum_partial_head_0(_i1.EnumTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -3156,7 +2950,7 @@ String _renderEnum_partial_head_0(_i1.EnumTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -3198,11 +2992,9 @@ String _renderEnum_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -3215,11 +3007,9 @@ String _renderEnum_partial_categorization_3(
   final buffer = StringBuffer();
   if (context1.hasCategoryNames == true) {
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3235,7 +3025,7 @@ String _renderEnum_partial_documentation_4(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -3269,7 +3059,7 @@ String _renderEnum_partial_constant_5(
 </dt>
 <dd>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -3293,11 +3083,9 @@ String __renderEnum_partial_constant_5_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3347,7 +3135,7 @@ String _renderEnum_partial_property_6(
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -3366,11 +3154,9 @@ String __renderEnum_partial_property_6_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3410,7 +3196,7 @@ String _renderEnum_partial_callable_7(
   buffer.write('''</span>''');
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''<span class="signature">(<wbr>''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''')
     <span class="returntype parameter">&#8594; ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
@@ -3428,7 +3214,7 @@ String _renderEnum_partial_callable_7(
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -3447,11 +3233,9 @@ String __renderEnum_partial_callable_7_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3482,33 +3266,29 @@ String _renderEnum_partial_search_sidebar_8(_i1.EnumTemplateData context0) {
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -3521,7 +3301,7 @@ String _renderEnum_partial_search_sidebar_8(_i1.EnumTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -3660,7 +3440,7 @@ String _renderError_partial_head_0(_i1.PackageTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -3668,14 +3448,12 @@ String _renderError_partial_head_0(_i1.PackageTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -3724,33 +3502,29 @@ String _renderError_partial_head_0(_i1.PackageTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -3795,33 +3569,29 @@ String _renderError_partial_search_sidebar_1(_i1.PackageTemplateData context0) {
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -3852,67 +3622,57 @@ String _renderError_partial_packages_2(_i1.PackageTemplateData context0) {
   final buffer = StringBuffer();
   buffer.write('''<ol>''');
   var context1 = context0.localPackages;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      if (context2.isFirstPackage == true) {
-        if (context2.hasDocumentedCategories == true) {
+  for (var context2 in context1) {
+    if (context2.isFirstPackage == true) {
+      if (context2.hasDocumentedCategories == true) {
+        buffer.writeln();
+        buffer.write('''
+      <li class="section-title">Topics</li>''');
+        var context3 = context2.documentedCategoriesSorted;
+        for (var context4 in context3) {
           buffer.writeln();
           buffer.write('''
-      <li class="section-title">Topics</li>''');
-          var context3 = context2.documentedCategoriesSorted;
-          if (context3 != null) {
-            for (var context4 in context3) {
-              buffer.writeln();
-              buffer.write('''
         <li>''');
-              buffer.write(context4.linkedName.toString());
-              buffer.write('''</li>''');
-            }
-          }
+          buffer.write(context4.linkedName.toString());
+          buffer.write('''</li>''');
         }
-        buffer.writeln();
-        buffer.write('''
-      <li class="section-title">Libraries</li>''');
       }
-      if (context2.isFirstPackage != true) {
+      buffer.writeln();
+      buffer.write('''
+      <li class="section-title">Libraries</li>''');
+    }
+    if (context2.isFirstPackage != true) {
+      buffer.writeln();
+      buffer.write('''
+      <li class="section-title">''');
+      buffer.writeEscaped(context2.name.toString());
+      buffer.write('''</li>''');
+    }
+    var context5 = context2.defaultCategory;
+    if (context5 != null) {
+      var context6 = context5.publicLibrariesSorted;
+      for (var context7 in context6) {
         buffer.writeln();
         buffer.write('''
-      <li class="section-title">''');
-        buffer.writeEscaped(context2.name.toString());
-        buffer.write('''</li>''');
-      }
-      var context5 = context2.defaultCategory;
-      if (context5 != null) {
-        var context6 = context5.publicLibrariesSorted;
-        if (context6 != null) {
-          for (var context7 in context6) {
-            buffer.writeln();
-            buffer.write('''
       <li>''');
-            buffer.write(context7.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context7.linkedName.toString());
+        buffer.write('''</li>''');
       }
-      var context8 = context2.categoriesWithPublicLibraries;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.writeln();
-          buffer.write('''
+    }
+    var context8 = context2.categoriesWithPublicLibraries;
+    for (var context9 in context8) {
+      buffer.writeln();
+      buffer.write('''
       <li class="section-subtitle">''');
-          buffer.writeEscaped(context9.name.toString());
-          buffer.write('''</li>''');
-          var context10 = context9.publicLibrariesSorted;
-          if (context10 != null) {
-            for (var context11 in context10) {
-              buffer.writeln();
-              buffer.write('''
+      buffer.writeEscaped(context9.name.toString());
+      buffer.write('''</li>''');
+      var context10 = context9.publicLibrariesSorted;
+      for (var context11 in context10) {
+        buffer.writeln();
+        buffer.write('''
         <li class="section-subitem">''');
-              buffer.write(context11.linkedName.toString());
-              buffer.write('''</li>''');
-            }
-          }
-        }
+        buffer.write(context11.linkedName.toString());
+        buffer.write('''</li>''');
       }
     }
   }
@@ -3983,170 +3743,152 @@ String renderExtension<T extends _i13.Extension>(
 
 <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
     <div>''');
-    buffer.write(_renderExtension_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-class">''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderExtension_partial_feature_set_2(context1, context0));
-    buffer.write(' ');
-    buffer.write(_renderExtension_partial_categorization_3(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderExtension_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-class">''');
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderExtension_partial_feature_set_2(context1, context0));
+  buffer.write(' ');
+  buffer.write(_renderExtension_partial_categorization_3(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.extension;
-  if (context2 != null) {
-    buffer.write('\n    ');
-    buffer.write(_renderExtension_partial_documentation_4(context2, context0));
-    buffer.writeln();
-    buffer.write('''
+  buffer.write('\n    ');
+  buffer.write(_renderExtension_partial_documentation_4(context2, context0));
+  buffer.writeln();
+  buffer.write('''
     <section>
         <dl class="dl-horizontal">
         <dt>on</dt>
         <dd>
             <ul class="comma-separated clazz-relationships">''');
-    var context3 = context2.extendedType;
-    if (context3 != null) {
-      buffer.writeln();
-      buffer.write('''
+  var context3 = context2.extendedType;
+  buffer.writeln();
+  buffer.write('''
             <li>''');
-      buffer.write(context3.linkedName.toString());
-      buffer.write('''</li>''');
-    }
-    buffer.writeln();
-    buffer.write('''
+  buffer.write(context3.linkedName.toString());
+  buffer.write('''</li>''');
+  buffer.writeln();
+  buffer.write('''
             </ul>
         </dd>
         </dl>
     </section>
 ''');
-    if (context2.hasPublicInstanceFields == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context2.hasPublicInstanceFields == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="instance-properties">
         <h2>Properties</h2>
 
         <dl class="properties">''');
-      var context4 = context2.publicInstanceFieldsSorted;
-      if (context4 != null) {
-        for (var context5 in context4) {
-          buffer.write('\n            ');
-          buffer.write(_renderExtension_partial_property_5(
-              context5, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context4 = context2.publicInstanceFieldsSorted;
+    for (var context5 in context4) {
+      buffer.write('\n            ');
+      buffer.write(
+          _renderExtension_partial_property_5(context5, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
         </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="instance-methods">
         <h2>Methods</h2>
         <dl class="callables">''');
-      var context6 = context2.publicInstanceMethodsSorted;
-      if (context6 != null) {
-        for (var context7 in context6) {
-          buffer.write('\n            ');
-          buffer.write(_renderExtension_partial_callable_6(
-              context7, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context6 = context2.publicInstanceMethodsSorted;
+    for (var context7 in context6) {
+      buffer.write('\n            ');
+      buffer.write(
+          _renderExtension_partial_callable_6(context7, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
         </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceOperators == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceOperators == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="operators">
         <h2>Operators</h2>
         <dl class="callables">''');
-      var context8 = context2.publicInstanceOperatorsSorted;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.write('\n            ');
-          buffer.write(_renderExtension_partial_callable_6(
-              context9, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context8 = context2.publicInstanceOperatorsSorted;
+    for (var context9 in context8) {
+      buffer.write('\n            ');
+      buffer.write(
+          _renderExtension_partial_callable_6(context9, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
         </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicVariableStaticFields == true) {
     buffer.writeln();
-    if (context2.hasPublicVariableStaticFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="static-properties">
         <h2>Static Properties</h2>
 
         <dl class="properties">''');
-      var context10 = context2.publicVariableStaticFieldsSorted;
-      if (context10 != null) {
-        for (var context11 in context10) {
-          buffer.write('\n            ');
-          buffer.write(_renderExtension_partial_property_5(
-              context11, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context10 = context2.publicVariableStaticFieldsSorted;
+    for (var context11 in context10) {
+      buffer.write('\n            ');
+      buffer.write(
+          _renderExtension_partial_property_5(context11, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
         </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicStaticMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicStaticMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="static-methods">
         <h2>Static Methods</h2>
         <dl class="callables">''');
-      var context12 = context2.publicStaticMethodsSorted;
-      if (context12 != null) {
-        for (var context13 in context12) {
-          buffer.write('\n            ');
-          buffer.write(_renderExtension_partial_callable_6(
-              context13, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context12 = context2.publicStaticMethodsSorted;
+    for (var context13 in context12) {
+      buffer.write('\n            ');
+      buffer.write(
+          _renderExtension_partial_callable_6(context13, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
         </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstantFields == true) {
     buffer.writeln();
-    if (context2.hasPublicConstantFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="constants">
         <h2>Constants</h2>
 
         <dl class="properties">''');
-      var context14 = context2.publicConstantFieldsSorted;
-      if (context14 != null) {
-        for (var context15 in context14) {
-          buffer.write('\n            ');
-          buffer.write(_renderExtension_partial_constant_7(
-              context15, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context14 = context2.publicConstantFieldsSorted;
+    for (var context15 in context14) {
+      buffer.write('\n            ');
+      buffer.write(
+          _renderExtension_partial_constant_7(context15, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
         </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   buffer.write('''
@@ -4159,9 +3901,9 @@ String renderExtension<T extends _i13.Extension>(
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForLibrary.toString());
@@ -4212,7 +3954,7 @@ String _renderExtension_partial_head_0<T extends _i13.Extension>(
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -4220,14 +3962,12 @@ String _renderExtension_partial_head_0<T extends _i13.Extension>(
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -4276,33 +4016,29 @@ String _renderExtension_partial_head_0<T extends _i13.Extension>(
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -4315,7 +4051,7 @@ String _renderExtension_partial_head_0<T extends _i13.Extension>(
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -4357,11 +4093,9 @@ String _renderExtension_partial_feature_set_2<T extends _i13.Extension>(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -4374,11 +4108,9 @@ String _renderExtension_partial_categorization_3<T extends _i13.Extension>(
   final buffer = StringBuffer();
   if (context1.hasCategoryNames == true) {
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -4394,7 +4126,7 @@ String _renderExtension_partial_documentation_4<T extends _i13.Extension>(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -4435,7 +4167,7 @@ String _renderExtension_partial_property_5<T extends _i13.Extension>(
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -4455,11 +4187,9 @@ String __renderExtension_partial_property_5_partial_categorization_0<
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -4502,7 +4232,7 @@ String _renderExtension_partial_callable_6<T extends _i13.Extension>(
   buffer.write('''</span>''');
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''<span class="signature">(<wbr>''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''')
     <span class="returntype parameter">&#8594; ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
@@ -4520,7 +4250,7 @@ String _renderExtension_partial_callable_6<T extends _i13.Extension>(
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -4540,11 +4270,9 @@ String __renderExtension_partial_callable_6_partial_categorization_0<
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -4592,7 +4320,7 @@ String _renderExtension_partial_constant_7<T extends _i13.Extension>(
 </dt>
 <dd>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -4617,11 +4345,9 @@ String __renderExtension_partial_constant_7_partial_categorization_0<
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -4654,33 +4380,29 @@ String _renderExtension_partial_search_sidebar_8<T extends _i13.Extension>(
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -4693,7 +4415,7 @@ String _renderExtension_partial_search_sidebar_8<T extends _i13.Extension>(
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -4766,39 +4488,35 @@ String renderFunction(_i1.FunctionTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderFunction_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-function">''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderFunction_partial_feature_set_2(context1, context0));
-    buffer.write(' ');
-    buffer.write(_renderFunction_partial_categorization_3(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderFunction_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-function">''');
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderFunction_partial_feature_set_2(context1, context0));
+  buffer.write(' ');
+  buffer.write(_renderFunction_partial_categorization_3(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.function;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
     <section class="multi-line-signature">
         ''');
-    buffer.write(
-        _renderFunction_partial_callable_multiline_4(context2, context0));
-    buffer.writeln();
-    buffer.write('''
+  buffer
+      .write(_renderFunction_partial_callable_multiline_4(context2, context0));
+  buffer.writeln();
+  buffer.write('''
     </section>
     ''');
-    buffer.write(_renderFunction_partial_documentation_5(context2, context0));
-    buffer.write('\n\n    ');
-    buffer.write(_renderFunction_partial_source_code_6(context2, context0));
-    buffer.writeln();
-  }
+  buffer.write(_renderFunction_partial_documentation_5(context2, context0));
+  buffer.write('\n\n    ');
+  buffer.write(_renderFunction_partial_source_code_6(context2, context0));
+  buffer.writeln();
   buffer.writeln();
   buffer.write('''
   </div> <!-- /.main-content -->
@@ -4809,9 +4527,9 @@ String renderFunction(_i1.FunctionTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForLibrary.toString());
@@ -4857,7 +4575,7 @@ String _renderFunction_partial_head_0(_i1.FunctionTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -4865,14 +4583,12 @@ String _renderFunction_partial_head_0(_i1.FunctionTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -4921,33 +4637,29 @@ String _renderFunction_partial_head_0(_i1.FunctionTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -4960,7 +4672,7 @@ String _renderFunction_partial_head_0(_i1.FunctionTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -5002,11 +4714,9 @@ String _renderFunction_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -5019,11 +4729,9 @@ String _renderFunction_partial_categorization_3(
   final buffer = StringBuffer();
   if (context1.hasCategoryNames == true) {
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -5040,14 +4748,12 @@ String _renderFunction_partial_callable_multiline_4(
 <div>
   <ol class="annotation-list">''');
     var context2 = context1.annotations;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write('''
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write('''
     <li>''');
-        buffer.write(context3.linkedNameWithParameters.toString());
-        buffer.write('''</li>''');
-      }
+      buffer.write(context3.linkedNameWithParameters.toString());
+      buffer.write('''</li>''');
     }
     buffer.writeln();
     buffer.write('''
@@ -5100,7 +4806,7 @@ String _renderFunction_partial_documentation_5(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -5139,33 +4845,29 @@ String _renderFunction_partial_search_sidebar_7(
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -5178,7 +4880,7 @@ String _renderFunction_partial_search_sidebar_7(
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -5250,66 +4952,56 @@ String renderIndex(_i1.PackageTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.defaultPackage;
-  if (context1 != null) {
-    buffer.write('\n      ');
-    buffer.write(_renderIndex_partial_documentation_1(context1, context0));
-  }
+  buffer.write('\n      ');
+  buffer.write(_renderIndex_partial_documentation_1(context1, context0));
   buffer.writeln();
   var context2 = context0.localPackages;
-  if (context2 != null) {
-    for (var context3 in context2) {
+  for (var context3 in context2) {
+    buffer.writeln();
+    buffer.write('''
+      <section class="summary">''');
+    if (context3.isFirstPackage == true) {
       buffer.writeln();
       buffer.write('''
-      <section class="summary">''');
-      if (context3.isFirstPackage == true) {
-        buffer.writeln();
-        buffer.write('''
           <h2>Libraries</h2>''');
-      }
-      if (context3.isFirstPackage != true) {
-        buffer.writeln();
-        buffer.write('''
-          <h2>''');
-        buffer.writeEscaped(context3.name.toString());
-        buffer.write('''</h2>''');
-      }
+    }
+    if (context3.isFirstPackage != true) {
       buffer.writeln();
       buffer.write('''
+          <h2>''');
+      buffer.writeEscaped(context3.name.toString());
+      buffer.write('''</h2>''');
+    }
+    buffer.writeln();
+    buffer.write('''
         <dl>''');
-      var context4 = context3.defaultCategory;
-      if (context4 != null) {
-        var context5 = context4.publicLibrariesSorted;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.write('\n          ');
-            buffer.write(_renderIndex_partial_library_2(
-                context6, context4, context3, context0));
-          }
-        }
-      }
-      var context7 = context3.categoriesWithPublicLibraries;
-      if (context7 != null) {
-        for (var context8 in context7) {
-          buffer.writeln();
-          buffer.write('''
-          <h3>''');
-          buffer.writeEscaped(context8.name.toString());
-          buffer.write('''</h3>''');
-          var context9 = context8.publicLibrariesSorted;
-          if (context9 != null) {
-            for (var context10 in context9) {
-              buffer.write('\n            ');
-              buffer.write(_renderIndex_partial_library_2(
-                  context10, context8, context3, context0));
-            }
-          }
-        }
+    var context4 = context3.defaultCategory;
+    if (context4 != null) {
+      var context5 = context4.publicLibrariesSorted;
+      for (var context6 in context5) {
+        buffer.write('\n          ');
+        buffer.write(_renderIndex_partial_library_2(
+            context6, context4, context3, context0));
       }
+    }
+    var context7 = context3.categoriesWithPublicLibraries;
+    for (var context8 in context7) {
       buffer.writeln();
       buffer.write('''
+          <h3>''');
+      buffer.writeEscaped(context8.name.toString());
+      buffer.write('''</h3>''');
+      var context9 = context8.publicLibrariesSorted;
+      for (var context10 in context9) {
+        buffer.write('\n            ');
+        buffer.write(_renderIndex_partial_library_2(
+            context10, context8, context3, context0));
+      }
+    }
+    buffer.writeln();
+    buffer.write('''
         </dl>
       </section>''');
-    }
   }
   buffer.writeln();
   buffer.write('''
@@ -5370,7 +5062,7 @@ String _renderIndex_partial_head_0(_i1.PackageTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -5378,14 +5070,12 @@ String _renderIndex_partial_head_0(_i1.PackageTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -5434,33 +5124,29 @@ String _renderIndex_partial_head_0(_i1.PackageTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -5503,7 +5189,7 @@ String _renderIndex_partial_documentation_1(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -5532,7 +5218,7 @@ String _renderIndex_partial_library_2(
 </dt>
 <dd>''');
   if (context3.isDocumented == true) {
-    buffer.write(context3.oneLineDoc.toString());
+    buffer.write(context3.oneLineDoc?.toString());
     buffer.write(' ');
     buffer.write(context3.extendedDocLink.toString());
   }
@@ -5552,11 +5238,9 @@ String __renderIndex_partial_library_2_partial_categorization_0(
   final buffer = StringBuffer();
   if (context3.hasCategoryNames == true) {
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.write('\n    ');
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.write('\n    ');
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -5574,33 +5258,29 @@ String _renderIndex_partial_search_sidebar_3(_i1.PackageTemplateData context0) {
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -5631,67 +5311,57 @@ String _renderIndex_partial_packages_4(_i1.PackageTemplateData context0) {
   final buffer = StringBuffer();
   buffer.write('''<ol>''');
   var context1 = context0.localPackages;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      if (context2.isFirstPackage == true) {
-        if (context2.hasDocumentedCategories == true) {
+  for (var context2 in context1) {
+    if (context2.isFirstPackage == true) {
+      if (context2.hasDocumentedCategories == true) {
+        buffer.writeln();
+        buffer.write('''
+      <li class="section-title">Topics</li>''');
+        var context3 = context2.documentedCategoriesSorted;
+        for (var context4 in context3) {
           buffer.writeln();
           buffer.write('''
-      <li class="section-title">Topics</li>''');
-          var context3 = context2.documentedCategoriesSorted;
-          if (context3 != null) {
-            for (var context4 in context3) {
-              buffer.writeln();
-              buffer.write('''
         <li>''');
-              buffer.write(context4.linkedName.toString());
-              buffer.write('''</li>''');
-            }
-          }
+          buffer.write(context4.linkedName.toString());
+          buffer.write('''</li>''');
         }
-        buffer.writeln();
-        buffer.write('''
-      <li class="section-title">Libraries</li>''');
       }
-      if (context2.isFirstPackage != true) {
+      buffer.writeln();
+      buffer.write('''
+      <li class="section-title">Libraries</li>''');
+    }
+    if (context2.isFirstPackage != true) {
+      buffer.writeln();
+      buffer.write('''
+      <li class="section-title">''');
+      buffer.writeEscaped(context2.name.toString());
+      buffer.write('''</li>''');
+    }
+    var context5 = context2.defaultCategory;
+    if (context5 != null) {
+      var context6 = context5.publicLibrariesSorted;
+      for (var context7 in context6) {
         buffer.writeln();
         buffer.write('''
-      <li class="section-title">''');
-        buffer.writeEscaped(context2.name.toString());
-        buffer.write('''</li>''');
-      }
-      var context5 = context2.defaultCategory;
-      if (context5 != null) {
-        var context6 = context5.publicLibrariesSorted;
-        if (context6 != null) {
-          for (var context7 in context6) {
-            buffer.writeln();
-            buffer.write('''
       <li>''');
-            buffer.write(context7.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context7.linkedName.toString());
+        buffer.write('''</li>''');
       }
-      var context8 = context2.categoriesWithPublicLibraries;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.writeln();
-          buffer.write('''
+    }
+    var context8 = context2.categoriesWithPublicLibraries;
+    for (var context9 in context8) {
+      buffer.writeln();
+      buffer.write('''
       <li class="section-subtitle">''');
-          buffer.writeEscaped(context9.name.toString());
-          buffer.write('''</li>''');
-          var context10 = context9.publicLibrariesSorted;
-          if (context10 != null) {
-            for (var context11 in context10) {
-              buffer.writeln();
-              buffer.write('''
+      buffer.writeEscaped(context9.name.toString());
+      buffer.write('''</li>''');
+      var context10 = context9.publicLibrariesSorted;
+      for (var context11 in context10) {
+        buffer.writeln();
+        buffer.write('''
         <li class="section-subitem">''');
-              buffer.write(context11.linkedName.toString());
-              buffer.write('''</li>''');
-            }
-          }
-        }
+        buffer.write(context11.linkedName.toString());
+        buffer.write('''</li>''');
       }
     }
   }
@@ -5761,269 +5431,211 @@ String renderLibrary(_i1.LibraryTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderLibrary_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-library">''');
-    buffer.write(context1.name.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderLibrary_partial_feature_set_2(context1, context0));
-    buffer.write(' ');
-    buffer.write(_renderLibrary_partial_categorization_3(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderLibrary_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-library">''');
+  buffer.write(context1.name.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderLibrary_partial_feature_set_2(context1, context0));
+  buffer.write(' ');
+  buffer.write(_renderLibrary_partial_categorization_3(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.library;
-  if (context2 != null) {
-    buffer.write('\n    ');
-    buffer.write(_renderLibrary_partial_documentation_4(context2, context0));
-  }
+  buffer.write('\n    ');
+  buffer.write(_renderLibrary_partial_documentation_4(context2, context0));
   buffer.writeln();
   var context3 = context0.library;
-  if (context3 != null) {
-    if (context3.hasPublicClasses == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context3.hasPublicClasses == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="classes">
       <h2>Classes</h2>
 
       <dl>''');
-      var context4 = context3.library;
-      if (context4 != null) {
-        var context5 = context4.publicClassesSorted;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.write('\n        ');
-            buffer.write(_renderLibrary_partial_container_5(
-                context6, context4, context3, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context4 = context3.library;
+    var context5 = context4.publicClassesSorted;
+    for (var context6 in context5) {
+      buffer.write('\n        ');
+      buffer.write(_renderLibrary_partial_container_5(
+          context6, context4, context3, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   var context7 = context0.library;
-  if (context7 != null) {
-    if (context7.hasPublicMixins == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context7.hasPublicMixins == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="mixins">
       <h2>Mixins</h2>
 
       <dl>''');
-      var context8 = context7.library;
-      if (context8 != null) {
-        var context9 = context8.publicMixinsSorted;
-        if (context9 != null) {
-          for (var context10 in context9) {
-            buffer.write('\n        ');
-            buffer.write(_renderLibrary_partial_container_5(
-                context10, context8, context7, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context8 = context7.library;
+    var context9 = context8.publicMixinsSorted;
+    for (var context10 in context9) {
+      buffer.write('\n        ');
+      buffer.write(_renderLibrary_partial_container_5(
+          context10, context8, context7, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   var context11 = context0.library;
-  if (context11 != null) {
-    if (context11.hasPublicExtensions == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context11.hasPublicExtensions == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="extensions">
       <h2>Extensions</h2>
 
       <dl>''');
-      var context12 = context11.library;
-      if (context12 != null) {
-        var context13 = context12.publicExtensionsSorted;
-        if (context13 != null) {
-          for (var context14 in context13) {
-            buffer.write('\n        ');
-            buffer.write(_renderLibrary_partial_extension_6(
-                context14, context12, context11, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context12 = context11.library;
+    var context13 = context12.publicExtensionsSorted;
+    for (var context14 in context13) {
+      buffer.write('\n        ');
+      buffer.write(_renderLibrary_partial_extension_6(
+          context14, context12, context11, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   var context15 = context0.library;
-  if (context15 != null) {
-    if (context15.hasPublicConstants == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context15.hasPublicConstants == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="constants">
       <h2>Constants</h2>
 
       <dl class="properties">''');
-      var context16 = context15.library;
-      if (context16 != null) {
-        var context17 = context16.publicConstantsSorted;
-        if (context17 != null) {
-          for (var context18 in context17) {
-            buffer.write('\n        ');
-            buffer.write(_renderLibrary_partial_constant_7(
-                context18, context16, context15, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context16 = context15.library;
+    var context17 = context16.publicConstantsSorted;
+    for (var context18 in context17) {
+      buffer.write('\n        ');
+      buffer.write(_renderLibrary_partial_constant_7(
+          context18, context16, context15, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   var context19 = context0.library;
-  if (context19 != null) {
-    if (context19.hasPublicProperties == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context19.hasPublicProperties == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="properties">
       <h2>Properties</h2>
 
       <dl class="properties">''');
-      var context20 = context19.library;
-      if (context20 != null) {
-        var context21 = context20.publicPropertiesSorted;
-        if (context21 != null) {
-          for (var context22 in context21) {
-            buffer.write('\n        ');
-            buffer.write(_renderLibrary_partial_property_8(
-                context22, context20, context19, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context20 = context19.library;
+    var context21 = context20.publicPropertiesSorted;
+    for (var context22 in context21) {
+      buffer.write('\n        ');
+      buffer.write(_renderLibrary_partial_property_8(
+          context22, context20, context19, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   var context23 = context0.library;
-  if (context23 != null) {
-    if (context23.hasPublicFunctions == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context23.hasPublicFunctions == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="functions">
       <h2>Functions</h2>
 
       <dl class="callables">''');
-      var context24 = context23.library;
-      if (context24 != null) {
-        var context25 = context24.publicFunctionsSorted;
-        if (context25 != null) {
-          for (var context26 in context25) {
-            buffer.write('\n        ');
-            buffer.write(_renderLibrary_partial_callable_9(
-                context26, context24, context23, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context24 = context23.library;
+    var context25 = context24.publicFunctionsSorted;
+    for (var context26 in context25) {
+      buffer.write('\n        ');
+      buffer.write(_renderLibrary_partial_callable_9(
+          context26, context24, context23, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   var context27 = context0.library;
-  if (context27 != null) {
-    if (context27.hasPublicEnums == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context27.hasPublicEnums == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="enums">
       <h2>Enums</h2>
 
       <dl>''');
-      var context28 = context27.library;
-      if (context28 != null) {
-        var context29 = context28.publicEnumsSorted;
-        if (context29 != null) {
-          for (var context30 in context29) {
-            buffer.write('\n        ');
-            buffer.write(_renderLibrary_partial_container_5(
-                context30, context28, context27, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context28 = context27.library;
+    var context29 = context28.publicEnumsSorted;
+    for (var context30 in context29) {
+      buffer.write('\n        ');
+      buffer.write(_renderLibrary_partial_container_5(
+          context30, context28, context27, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   var context31 = context0.library;
-  if (context31 != null) {
-    if (context31.hasPublicTypedefs == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context31.hasPublicTypedefs == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="typedefs">
       <h2>Typedefs</h2>
 
       <dl>''');
-      var context32 = context31.library;
-      if (context32 != null) {
-        var context33 = context32.publicTypedefsSorted;
-        if (context33 != null) {
-          for (var context34 in context33) {
-            buffer.write('\n          ');
-            buffer.write(_renderLibrary_partial_typedef_10(
-                context34, context32, context31, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context32 = context31.library;
+    var context33 = context32.publicTypedefsSorted;
+    for (var context34 in context33) {
+      buffer.write('\n          ');
+      buffer.write(_renderLibrary_partial_typedef_10(
+          context34, context32, context31, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   var context35 = context0.library;
-  if (context35 != null) {
-    if (context35.hasPublicExceptions == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context35.hasPublicExceptions == true) {
+    buffer.writeln();
+    buffer.write('''
     <section class="summary offset-anchor" id="exceptions">
       <h2>Exceptions / Errors</h2>
 
       <dl>''');
-      var context36 = context35.library;
-      if (context36 != null) {
-        var context37 = context36.publicExceptionsSorted;
-        if (context37 != null) {
-          for (var context38 in context37) {
-            buffer.write('\n        ');
-            buffer.write(_renderLibrary_partial_container_5(
-                context38, context36, context35, context0));
-          }
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context36 = context35.library;
+    var context37 = context36.publicExceptionsSorted;
+    for (var context38 in context37) {
+      buffer.write('\n        ');
+      buffer.write(_renderLibrary_partial_container_5(
+          context38, context36, context35, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   buffer.write('''
@@ -6036,9 +5648,9 @@ String renderLibrary(_i1.LibraryTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5><span class="package-name">''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write('''</span> <span class="package-kind">''');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</span></h5>
     ''');
   buffer.write(_renderLibrary_partial_packages_12(context0));
@@ -6093,7 +5705,7 @@ String _renderLibrary_partial_head_0(_i1.LibraryTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -6101,14 +5713,12 @@ String _renderLibrary_partial_head_0(_i1.LibraryTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -6157,33 +5767,29 @@ String _renderLibrary_partial_head_0(_i1.LibraryTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -6196,7 +5802,7 @@ String _renderLibrary_partial_head_0(_i1.LibraryTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -6238,11 +5844,9 @@ String _renderLibrary_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -6255,11 +5859,9 @@ String _renderLibrary_partial_categorization_3(
   final buffer = StringBuffer();
   if (context1.hasCategoryNames == true) {
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -6275,7 +5877,7 @@ String _renderLibrary_partial_documentation_4(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -6309,7 +5911,7 @@ String _renderLibrary_partial_container_5(
 </dt>
 <dd>
   ''');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.writeln();
@@ -6328,11 +5930,9 @@ String __renderLibrary_partial_container_5_partial_categorization_0(
   final buffer = StringBuffer();
   if (context3.hasCategoryNames == true) {
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.write('\n    ');
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.write('\n    ');
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -6363,7 +5963,7 @@ String _renderLibrary_partial_extension_6(
 </dt>
 <dd>
     ''');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.writeln();
@@ -6383,11 +5983,9 @@ String __renderLibrary_partial_extension_6_partial_categorization_0(
   final buffer = StringBuffer();
   if (context3.hasCategoryNames == true) {
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.write('\n    ');
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.write('\n    ');
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -6422,7 +6020,7 @@ String _renderLibrary_partial_constant_7(
 </dt>
 <dd>
   ''');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -6449,11 +6047,9 @@ String __renderLibrary_partial_constant_7_partial_categorization_0(
   final buffer = StringBuffer();
   if (context3.hasCategoryNames == true) {
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.write('\n    ');
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.write('\n    ');
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -6509,7 +6105,7 @@ String _renderLibrary_partial_property_8(
   }
   buffer.write('''>
   ''');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -6531,11 +6127,9 @@ String __renderLibrary_partial_property_8_partial_categorization_0(
   final buffer = StringBuffer();
   if (context3.hasCategoryNames == true) {
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.write('\n    ');
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.write('\n    ');
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -6581,7 +6175,7 @@ String _renderLibrary_partial_callable_9(
   buffer.write('''</span>''');
   buffer.write(context3.linkedGenericParameters.toString());
   buffer.write('''<span class="signature">(<wbr>''');
-  buffer.write(context3.linkedParamsNoMetadata.toString());
+  buffer.write(context3.linkedParamsNoMetadata?.toString());
   buffer.write(''')
     <span class="returntype parameter">&#8594; ''');
   buffer.write(context3.modelType.returnType.linkedName.toString());
@@ -6599,7 +6193,7 @@ String _renderLibrary_partial_callable_9(
   }
   buffer.write('''>
   ''');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -6621,11 +6215,9 @@ String __renderLibrary_partial_callable_9_partial_categorization_0(
   final buffer = StringBuffer();
   if (context3.hasCategoryNames == true) {
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.write('\n    ');
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.write('\n    ');
+      buffer.write(context5!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -6657,51 +6249,49 @@ String _renderLibrary_partial_typedef_10(
   final buffer = StringBuffer();
   if (context3.isCallable == true) {
     var context4 = context3.asCallable;
-    if (context4 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <dt id="''');
-      buffer.writeEscaped(context4.htmlId.toString());
-      buffer.write('''" class="callable''');
-      if (context4.isInherited == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''">
+    buffer.writeEscaped(context4.htmlId.toString());
+    buffer.write('''" class="callable''');
+    if (context4.isInherited == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''">
     <span class="name''');
-      if (context4.isDeprecated == true) {
-        buffer.write(''' deprecated''');
-      }
-      buffer.write('''">''');
-      buffer.write(context4.linkedName.toString());
-      buffer.write('''</span>''');
-      buffer.write(context4.linkedGenericParameters.toString());
-      buffer.write('''<span class="signature">
+    if (context4.isDeprecated == true) {
+      buffer.write(''' deprecated''');
+    }
+    buffer.write('''">''');
+    buffer.write(context4.linkedName.toString());
+    buffer.write('''</span>''');
+    buffer.write(context4.linkedGenericParameters.toString());
+    buffer.write('''<span class="signature">
       <span class="returntype parameter">= ''');
-      buffer.write(context4.modelType.linkedName.toString());
-      buffer.write('''</span>
+    buffer.write(context4.modelType.linkedName.toString());
+    buffer.write('''</span>
     </span>
     ''');
-      buffer.write(__renderLibrary_partial_typedef_10_partial_categorization_0(
-          context4, context3, context2, context1, context0));
-      buffer.writeln();
-      buffer.write('''
+    buffer.write(__renderLibrary_partial_typedef_10_partial_categorization_0(
+        context4, context3, context2, context1, context0));
+    buffer.writeln();
+    buffer.write('''
   </dt>
   <dd''');
-      if (context4.isInherited == true) {
-        buffer.write(''' class="inherited"''');
-      }
-      buffer.write('''>
+    if (context4.isInherited == true) {
+      buffer.write(''' class="inherited"''');
+    }
+    buffer.write('''>
     ''');
-      buffer.write(context4.oneLineDoc.toString());
-      buffer.write(' ');
-      buffer.write(context4.extendedDocLink.toString());
-      buffer.write('\n    ');
-      buffer.write(__renderLibrary_partial_typedef_10_partial_features_1(
-          context4, context3, context2, context1, context0));
-      buffer.writeln();
-      buffer.write('''
+    buffer.write(context4.oneLineDoc?.toString());
+    buffer.write(' ');
+    buffer.write(context4.extendedDocLink.toString());
+    buffer.write('\n    ');
+    buffer.write(__renderLibrary_partial_typedef_10_partial_features_1(
+        context4, context3, context2, context1, context0));
+    buffer.writeln();
+    buffer.write('''
   </dd>''');
-    }
   }
   if (context3.isCallable != true) {
     buffer.write('\n  ');
@@ -6722,11 +6312,9 @@ String __renderLibrary_partial_typedef_10_partial_categorization_0(
   final buffer = StringBuffer();
   if (context4.hasCategoryNames == true) {
     var context5 = context4.displayedCategories;
-    if (context5 != null) {
-      for (var context6 in context5) {
-        buffer.write('\n    ');
-        buffer.write(context6.categoryLabel.toString());
-      }
+    for (var context6 in context5) {
+      buffer.write('\n    ');
+      buffer.write(context6.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -6792,7 +6380,7 @@ String __renderLibrary_partial_typedef_10_partial_type_2(
   }
   buffer.write('''>
   ''');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -6816,11 +6404,9 @@ String
   final buffer = StringBuffer();
   if (context3.hasCategoryNames == true) {
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.write('\n    ');
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.write('\n    ');
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -6855,33 +6441,29 @@ String _renderLibrary_partial_search_sidebar_11(
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -6894,7 +6476,7 @@ String _renderLibrary_partial_search_sidebar_11(
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -6912,67 +6494,57 @@ String _renderLibrary_partial_packages_12(_i1.LibraryTemplateData context0) {
   final buffer = StringBuffer();
   buffer.write('''<ol>''');
   var context1 = context0.localPackages;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      if (context2.isFirstPackage == true) {
-        if (context2.hasDocumentedCategories == true) {
+  for (var context2 in context1) {
+    if (context2.isFirstPackage == true) {
+      if (context2.hasDocumentedCategories == true) {
+        buffer.writeln();
+        buffer.write('''
+      <li class="section-title">Topics</li>''');
+        var context3 = context2.documentedCategoriesSorted;
+        for (var context4 in context3) {
           buffer.writeln();
           buffer.write('''
-      <li class="section-title">Topics</li>''');
-          var context3 = context2.documentedCategoriesSorted;
-          if (context3 != null) {
-            for (var context4 in context3) {
-              buffer.writeln();
-              buffer.write('''
         <li>''');
-              buffer.write(context4.linkedName.toString());
-              buffer.write('''</li>''');
-            }
-          }
+          buffer.write(context4.linkedName.toString());
+          buffer.write('''</li>''');
         }
-        buffer.writeln();
-        buffer.write('''
-      <li class="section-title">Libraries</li>''');
       }
-      if (context2.isFirstPackage != true) {
+      buffer.writeln();
+      buffer.write('''
+      <li class="section-title">Libraries</li>''');
+    }
+    if (context2.isFirstPackage != true) {
+      buffer.writeln();
+      buffer.write('''
+      <li class="section-title">''');
+      buffer.writeEscaped(context2.name.toString());
+      buffer.write('''</li>''');
+    }
+    var context5 = context2.defaultCategory;
+    if (context5 != null) {
+      var context6 = context5.publicLibrariesSorted;
+      for (var context7 in context6) {
         buffer.writeln();
         buffer.write('''
-      <li class="section-title">''');
-        buffer.writeEscaped(context2.name.toString());
-        buffer.write('''</li>''');
-      }
-      var context5 = context2.defaultCategory;
-      if (context5 != null) {
-        var context6 = context5.publicLibrariesSorted;
-        if (context6 != null) {
-          for (var context7 in context6) {
-            buffer.writeln();
-            buffer.write('''
       <li>''');
-            buffer.write(context7.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context7.linkedName.toString());
+        buffer.write('''</li>''');
       }
-      var context8 = context2.categoriesWithPublicLibraries;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.writeln();
-          buffer.write('''
+    }
+    var context8 = context2.categoriesWithPublicLibraries;
+    for (var context9 in context8) {
+      buffer.writeln();
+      buffer.write('''
       <li class="section-subtitle">''');
-          buffer.writeEscaped(context9.name.toString());
-          buffer.write('''</li>''');
-          var context10 = context9.publicLibrariesSorted;
-          if (context10 != null) {
-            for (var context11 in context10) {
-              buffer.writeln();
-              buffer.write('''
+      buffer.writeEscaped(context9.name.toString());
+      buffer.write('''</li>''');
+      var context10 = context9.publicLibrariesSorted;
+      for (var context11 in context10) {
+        buffer.writeln();
+        buffer.write('''
         <li class="section-subitem">''');
-              buffer.write(context11.linkedName.toString());
-              buffer.write('''</li>''');
-            }
-          }
-        }
+        buffer.write(context11.linkedName.toString());
+        buffer.write('''</li>''');
       }
     }
   }
@@ -7042,39 +6614,34 @@ String renderMethod(_i1.MethodTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderMethod_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-method">''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderMethod_partial_feature_set_2(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderMethod_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-method">''');
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderMethod_partial_feature_set_2(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.method;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
     <section class="multi-line-signature">
       ''');
-    buffer
-        .write(_renderMethod_partial_callable_multiline_3(context2, context0));
-    buffer.write('\n      ');
-    buffer.write(_renderMethod_partial_features_4(context2, context0));
-    buffer.writeln();
-    buffer.write('''
+  buffer.write(_renderMethod_partial_callable_multiline_3(context2, context0));
+  buffer.write('\n      ');
+  buffer.write(_renderMethod_partial_features_4(context2, context0));
+  buffer.writeln();
+  buffer.write('''
     </section>
     ''');
-    buffer.write(_renderMethod_partial_documentation_5(context2, context0));
-    buffer.write('\n\n    ');
-    buffer.write(_renderMethod_partial_source_code_6(context2, context0));
-    buffer.writeln();
-  }
+  buffer.write(_renderMethod_partial_documentation_5(context2, context0));
+  buffer.write('\n\n    ');
+  buffer.write(_renderMethod_partial_source_code_6(context2, context0));
+  buffer.writeln();
   buffer.writeln();
   buffer.write('''
   </div> <!-- /.main-content -->
@@ -7085,9 +6652,9 @@ String renderMethod(_i1.MethodTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForContainer.toString());
@@ -7133,7 +6700,7 @@ String _renderMethod_partial_head_0(_i1.MethodTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -7141,14 +6708,12 @@ String _renderMethod_partial_head_0(_i1.MethodTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -7197,33 +6762,29 @@ String _renderMethod_partial_head_0(_i1.MethodTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -7236,7 +6797,7 @@ String _renderMethod_partial_head_0(_i1.MethodTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -7278,11 +6839,9 @@ String _renderMethod_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -7299,14 +6858,12 @@ String _renderMethod_partial_callable_multiline_3(
 <div>
   <ol class="annotation-list">''');
     var context2 = context1.annotations;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write('''
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write('''
     <li>''');
-        buffer.write(context3.linkedNameWithParameters.toString());
-        buffer.write('''</li>''');
-      }
+      buffer.write(context3.linkedNameWithParameters.toString());
+      buffer.write('''</li>''');
     }
     buffer.writeln();
     buffer.write('''
@@ -7372,7 +6929,7 @@ String _renderMethod_partial_documentation_5(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -7410,33 +6967,29 @@ String _renderMethod_partial_search_sidebar_7(_i1.MethodTemplateData context0) {
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -7449,7 +7002,7 @@ String _renderMethod_partial_search_sidebar_7(_i1.MethodTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -7521,281 +7074,255 @@ String renderMixin(_i1.MixinTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderMixin_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-mixin">''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderMixin_partial_feature_set_2(context1, context0));
-    buffer.write(' ');
-    buffer.write(_renderMixin_partial_categorization_3(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderMixin_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-mixin">''');
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderMixin_partial_feature_set_2(context1, context0));
+  buffer.write(' ');
+  buffer.write(_renderMixin_partial_categorization_3(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.mixin;
-  if (context2 != null) {
-    buffer.write('\n    ');
-    buffer.write(_renderMixin_partial_documentation_4(context2, context0));
+  buffer.write('\n    ');
+  buffer.write(_renderMixin_partial_documentation_4(context2, context0));
+  buffer.writeln();
+  if (context2.hasModifiers == true) {
     buffer.writeln();
-    if (context2.hasModifiers == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section>
       <dl class="dl-horizontal">''');
-      if (context2.hasPublicSuperclassConstraints == true) {
-        buffer.writeln();
-        buffer.write('''
+    if (context2.hasPublicSuperclassConstraints == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Superclass Constraints</dt>
         <dd><ul class="comma-separated dark mixin-relationships">''');
-        var context3 = context2.publicSuperclassConstraints;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context4.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context3 = context2.publicSuperclassConstraints;
+      for (var context4 in context3) {
         buffer.writeln();
         buffer.write('''
-        </ul></dd>''');
+          <li>''');
+        buffer.write(context4.linkedName.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
-      if (context2.hasPublicSuperChainReversed == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    if (context2.hasPublicSuperChainReversed == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Inheritance</dt>
         <dd><ul class="gt-separated dark mixin-relationships">
           <li>''');
-        buffer.write(context0.linkedObjectType.toString());
-        buffer.write('''</li>''');
-        var context5 = context2.publicSuperChainReversed;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context6.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      buffer.write(context0.linkedObjectType.toString());
+      buffer.write('''</li>''');
+      var context5 = context2.publicSuperChainReversed;
+      for (var context6 in context5) {
         buffer.writeln();
         buffer.write('''
           <li>''');
-        buffer.write(context2.name.toString());
-        buffer.write('''</li>
-        </ul></dd>''');
+        buffer.write(context6.linkedName.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
-      if (context2.hasPublicInterfaces == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
+          <li>''');
+      buffer.write(context2.name.toString());
+      buffer.write('''</li>
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    if (context2.hasPublicInterfaces == true) {
+      buffer.writeln();
+      buffer.write('''
         <dt>Implements</dt>
         <dd>
           <ul class="comma-separated mixin-relationships">''');
-        var context7 = context2.publicInterfaces;
-        if (context7 != null) {
-          for (var context8 in context7) {
-            buffer.writeln();
-            buffer.write('''
-            <li>''');
-            buffer.write(context8.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context7 = context2.publicInterfaces;
+      for (var context8 in context7) {
         buffer.writeln();
         buffer.write('''
+            <li>''');
+        buffer.write(context8.linkedName.toString());
+        buffer.write('''</li>''');
+      }
+      buffer.writeln();
+      buffer.write('''
           </ul>
         </dd>''');
-      }
+    }
+    buffer.writeln();
+    if (context2.hasPublicImplementors == true) {
       buffer.writeln();
-      if (context2.hasPublicImplementors == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
         <dt>Mixin Applications</dt>
         <dd>
           <ul class="comma-separated mixin-relationships">''');
-        var context9 = context2.publicImplementorsSorted;
-        if (context9 != null) {
-          for (var context10 in context9) {
-            buffer.writeln();
-            buffer.write('''
-            <li>''');
-            buffer.write(context10.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context9 = context2.publicImplementorsSorted;
+      for (var context10 in context9) {
         buffer.writeln();
         buffer.write('''
+            <li>''');
+        buffer.write(context10.linkedName.toString());
+        buffer.write('''</li>''');
+      }
+      buffer.writeln();
+      buffer.write('''
           </ul>
         </dd>''');
-      }
+    }
+    buffer.writeln();
+    if (context2.hasAnnotations == true) {
       buffer.writeln();
-      if (context2.hasAnnotations == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
         <dt>Annotations</dt>
         <dd><ul class="annotation-list mixin-relationships">''');
-        var context11 = context2.annotations;
-        if (context11 != null) {
-          for (var context12 in context11) {
-            buffer.writeln();
-            buffer.write('''
-          <li>''');
-            buffer.write(context12.linkedNameWithParameters.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context11 = context2.annotations;
+      for (var context12 in context11) {
         buffer.writeln();
         buffer.write('''
-        </ul></dd>''');
+          <li>''');
+        buffer.write(context12.linkedNameWithParameters.toString());
+        buffer.write('''</li>''');
       }
       buffer.writeln();
       buffer.write('''
+        </ul></dd>''');
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceFields == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceFields == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="instance-properties">
+    if (context2.publicInheritedInstanceFields == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="instance-properties">
       <h2>Properties</h2>
 
       <dl class="properties">''');
-      var context13 = context2.publicInstanceFields;
-      if (context13 != null) {
-        for (var context14 in context13) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderMixin_partial_property_5(context14, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context13 = context2.publicInstanceFields;
+    for (var context14 in context13) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderMixin_partial_property_5(context14, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceMethods == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="instance-methods">
+    if (context2.publicInheritedInstanceMethods == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="instance-methods">
       <h2>Methods</h2>
       <dl class="callables">''');
-      var context15 = context2.publicInstanceMethods;
-      if (context15 != null) {
-        for (var context16 in context15) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderMixin_partial_callable_6(context16, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context15 = context2.publicInstanceMethods;
+    for (var context16 in context15) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderMixin_partial_callable_6(context16, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceOperators == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceOperators == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor''');
-      if (context2.publicInheritedInstanceOperators == true) {
-        buffer.write(''' inherited''');
-      }
-      buffer.write('''" id="operators">
+    if (context2.publicInheritedInstanceOperators == true) {
+      buffer.write(''' inherited''');
+    }
+    buffer.write('''" id="operators">
       <h2>Operators</h2>
       <dl class="callables">''');
-      var context17 = context2.publicInstanceOperatorsSorted;
-      if (context17 != null) {
-        for (var context18 in context17) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderMixin_partial_callable_6(context18, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context17 = context2.publicInstanceOperatorsSorted;
+    for (var context18 in context17) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderMixin_partial_callable_6(context18, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicVariableStaticFields == true) {
     buffer.writeln();
-    if (context2.hasPublicVariableStaticFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="static-properties">
       <h2>Static Properties</h2>
 
       <dl class="properties">''');
-      var context19 = context2.publicVariableStaticFieldsSorted;
-      if (context19 != null) {
-        for (var context20 in context19) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderMixin_partial_property_5(context20, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context19 = context2.publicVariableStaticFieldsSorted;
+    for (var context20 in context19) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderMixin_partial_property_5(context20, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicStaticMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicStaticMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="static-methods">
       <h2>Static Methods</h2>
       <dl class="callables">''');
-      var context21 = context2.publicStaticMethods;
-      if (context21 != null) {
-        for (var context22 in context21) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderMixin_partial_callable_6(context22, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context21 = context2.publicStaticMethods;
+    for (var context22 in context21) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderMixin_partial_callable_6(context22, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstantFields == true) {
     buffer.writeln();
-    if (context2.hasPublicConstantFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
     <section class="summary offset-anchor" id="constants">
       <h2>Constants</h2>
 
       <dl class="properties">''');
-      var context23 = context2.publicConstantFieldsSorted;
-      if (context23 != null) {
-        for (var context24 in context23) {
-          buffer.write('\n        ');
-          buffer.write(
-              _renderMixin_partial_constant_7(context24, context2, context0));
-        }
-      }
-      buffer.writeln();
-      buffer.write('''
+    var context23 = context2.publicConstantFieldsSorted;
+    for (var context24 in context23) {
+      buffer.write('\n        ');
+      buffer.write(
+          _renderMixin_partial_constant_7(context24, context2, context0));
+    }
+    buffer.writeln();
+    buffer.write('''
       </dl>
     </section>''');
-    }
   }
   buffer.writeln();
   buffer.write('''
@@ -7807,9 +7334,9 @@ String renderMixin(_i1.MixinTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForLibrary.toString());
@@ -7859,7 +7386,7 @@ String _renderMixin_partial_head_0(_i1.MixinTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -7867,14 +7394,12 @@ String _renderMixin_partial_head_0(_i1.MixinTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -7923,33 +7448,29 @@ String _renderMixin_partial_head_0(_i1.MixinTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -7962,7 +7483,7 @@ String _renderMixin_partial_head_0(_i1.MixinTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -8004,11 +7525,9 @@ String _renderMixin_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -8021,11 +7540,9 @@ String _renderMixin_partial_categorization_3(
   final buffer = StringBuffer();
   if (context1.hasCategoryNames == true) {
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -8041,7 +7558,7 @@ String _renderMixin_partial_documentation_4(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -8080,7 +7597,7 @@ String _renderMixin_partial_property_5(
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -8099,11 +7616,9 @@ String __renderMixin_partial_property_5_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -8143,7 +7658,7 @@ String _renderMixin_partial_callable_6(
   buffer.write('''</span>''');
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''<span class="signature">(<wbr>''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''')
     <span class="returntype parameter">&#8594; ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
@@ -8161,7 +7676,7 @@ String _renderMixin_partial_callable_6(
   }
   buffer.write('''>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -8180,11 +7695,9 @@ String __renderMixin_partial_callable_6_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -8229,7 +7742,7 @@ String _renderMixin_partial_constant_7(
 </dt>
 <dd>
   ''');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('\n  ');
@@ -8253,11 +7766,9 @@ String __renderMixin_partial_constant_7_partial_categorization_0(
   final buffer = StringBuffer();
   if (context2.hasCategoryNames == true) {
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.write('\n    ');
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.write('\n    ');
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -8288,33 +7799,29 @@ String _renderMixin_partial_search_sidebar_8(_i1.MixinTemplateData context0) {
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -8327,7 +7834,7 @@ String _renderMixin_partial_search_sidebar_8(_i1.MixinTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -8399,53 +7906,49 @@ String renderProperty(_i1.PropertyTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderProperty_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-property">''');
-    buffer.writeEscaped(context1.name.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderProperty_partial_feature_set_2(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderProperty_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-property">''');
+  buffer.writeEscaped(context1.name.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderProperty_partial_feature_set_2(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   var context2 = context0.self;
-  if (context2 != null) {
-    if (context2.hasNoGetterSetter == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context2.hasNoGetterSetter == true) {
+    buffer.writeln();
+    buffer.write('''
         <section class="multi-line-signature">
           ''');
-      buffer.write(context2.modelType.linkedName.toString());
-      buffer.write('\n          ');
-      buffer.write(_renderProperty_partial_name_summary_3(context2, context0));
-      buffer.write('\n          ');
-      buffer.write(_renderProperty_partial_features_4(context2, context0));
-      buffer.writeln();
-      buffer.write('''
+    buffer.write(context2.modelType.linkedName.toString());
+    buffer.write('\n          ');
+    buffer.write(_renderProperty_partial_name_summary_3(context2, context0));
+    buffer.write('\n          ');
+    buffer.write(_renderProperty_partial_features_4(context2, context0));
+    buffer.writeln();
+    buffer.write('''
         </section>
         ''');
-      buffer.write(_renderProperty_partial_documentation_5(context2, context0));
+    buffer.write(_renderProperty_partial_documentation_5(context2, context0));
+    buffer.write('\n        ');
+    buffer.write(_renderProperty_partial_source_code_6(context2, context0));
+  }
+  buffer.writeln();
+  if (context2.hasGetterOrSetter == true) {
+    if (context2.hasGetter == true) {
       buffer.write('\n        ');
-      buffer.write(_renderProperty_partial_source_code_6(context2, context0));
+      buffer
+          .write(_renderProperty_partial_accessor_getter_7(context2, context0));
     }
     buffer.writeln();
-    if (context2.hasGetterOrSetter == true) {
-      if (context2.hasGetter == true) {
-        buffer.write('\n        ');
-        buffer.write(
-            _renderProperty_partial_accessor_getter_7(context2, context0));
-      }
-      buffer.writeln();
-      if (context2.hasSetter == true) {
-        buffer.write('\n        ');
-        buffer.write(
-            _renderProperty_partial_accessor_setter_8(context2, context0));
-      }
+    if (context2.hasSetter == true) {
+      buffer.write('\n        ');
+      buffer
+          .write(_renderProperty_partial_accessor_setter_8(context2, context0));
     }
   }
   buffer.writeln();
@@ -8458,9 +7961,9 @@ String renderProperty(_i1.PropertyTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForContainer.toString());
@@ -8506,7 +8009,7 @@ String _renderProperty_partial_head_0(_i1.PropertyTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -8514,14 +8017,12 @@ String _renderProperty_partial_head_0(_i1.PropertyTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -8570,33 +8071,29 @@ String _renderProperty_partial_head_0(_i1.PropertyTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -8609,7 +8106,7 @@ String _renderProperty_partial_head_0(_i1.PropertyTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -8651,11 +8148,9 @@ String _renderProperty_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -8701,7 +8196,7 @@ String _renderProperty_partial_documentation_5(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -8814,7 +8309,7 @@ String __renderProperty_partial_accessor_getter_7_partial_documentation_2(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context2.documentationAsHtml.toString());
+    buffer.write(context2.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -8860,7 +8355,7 @@ String _renderProperty_partial_accessor_setter_8(
         __renderProperty_partial_accessor_setter_8_partial_name_summary_0(
             context2, context1, context0));
     buffer.write('''<span class="signature">(<wbr>''');
-    buffer.write(context2.linkedParamsNoMetadata.toString());
+    buffer.write(context2.linkedParamsNoMetadata?.toString());
     buffer.write(''')</span>
   ''');
     buffer.write(__renderProperty_partial_accessor_setter_8_partial_features_1(
@@ -8930,7 +8425,7 @@ String __renderProperty_partial_accessor_setter_8_partial_documentation_2(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context2.documentationAsHtml.toString());
+    buffer.write(context2.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -8971,33 +8466,29 @@ String _renderProperty_partial_search_sidebar_9(
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -9010,7 +8501,7 @@ String _renderProperty_partial_search_sidebar_9(
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -9079,246 +8570,222 @@ String renderSidebarForContainer<T extends _i18.Documentable>(
   final buffer = StringBuffer();
   buffer.write('''<ol>''');
   var context1 = context0.container;
-  if (context1 != null) {
-    buffer.writeln();
-    if (context1.isClass == true) {
-      if (context1.hasPublicConstructors == true) {
+  buffer.writeln();
+  if (context1.isClass == true) {
+    if (context1.hasPublicConstructors == true) {
+      buffer.writeln();
+      buffer.write('''
+    <li class="section-title"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#constructors">Constructors</a></li>''');
+      var context2 = context1.publicConstructorsSorted;
+      for (var context3 in context2) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#constructors">Constructors</a></li>''');
-        var context2 = context1.publicConstructorsSorted;
-        if (context2 != null) {
-          for (var context3 in context2) {
-            buffer.writeln();
-            buffer.write('''
     <li><a''');
-            if (context3.isDeprecated == true) {
-              buffer.write(''' class="deprecated"''');
-            }
-            buffer.write(''' href="''');
-            buffer.write(context3.href.toString());
-            buffer.write('''">''');
-            buffer.writeEscaped(context3.shortName.toString());
-            buffer.write('''</a></li>''');
-          }
+        if (context3.isDeprecated == true) {
+          buffer.write(''' class="deprecated"''');
         }
+        buffer.write(''' href="''');
+        buffer.write(context3.href?.toString());
+        buffer.write('''">''');
+        buffer.writeEscaped(context3.shortName?.toString());
+        buffer.write('''</a></li>''');
       }
     }
-    buffer.writeln();
-    if (context1.isEnum == true) {
-      if (context1.hasPublicConstantFields == true) {
+  }
+  buffer.writeln();
+  if (context1.isEnum == true) {
+    if (context1.hasPublicConstantFields == true) {
+      buffer.writeln();
+      buffer.write('''
+    <li class="section-title"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#constants">Constants</a></li>''');
+      var context4 = context1.publicConstantFieldsSorted;
+      for (var context5 in context4) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#constants">Constants</a></li>''');
-        var context4 = context1.publicConstantFieldsSorted;
-        if (context4 != null) {
-          for (var context5 in context4) {
-            buffer.writeln();
-            buffer.write('''
     <li>''');
-            buffer.write(context5.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context5.linkedName.toString());
+        buffer.write('''</li>''');
       }
     }
-    buffer.writeln();
-    if (context1.isClassOrEnum == true) {
-      if (context1.hasPublicInstanceFields == true) {
-        buffer.writeln();
-        buffer.write('''
+  }
+  buffer.writeln();
+  if (context1.isClassOrEnum == true) {
+    if (context1.hasPublicInstanceFields == true) {
+      buffer.writeln();
+      buffer.write('''
     <li class="section-title''');
-        if (context1.publicInheritedInstanceFields == true) {
-          buffer.write(''' inherited''');
-        }
-        buffer.write('''">
+      if (context1.publicInheritedInstanceFields == true) {
+        buffer.write(''' inherited''');
+      }
+      buffer.write('''">
       <a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#instance-properties">Properties</a>
+      buffer.write(context1.href?.toString());
+      buffer.write('''#instance-properties">Properties</a>
     </li>''');
-        var context6 = context1.publicInstanceFieldsSorted;
-        if (context6 != null) {
-          for (var context7 in context6) {
-            buffer.writeln();
-            buffer.write('''
+      var context6 = context1.publicInstanceFieldsSorted;
+      for (var context7 in context6) {
+        buffer.writeln();
+        buffer.write('''
     <li''');
-            if (context7.isInherited == true) {
-              buffer.write(''' class="inherited"''');
-            }
-            buffer.write('''>''');
-            buffer.write(context7.linkedName.toString());
-            buffer.write('''</li>''');
-          }
+        if (context7.isInherited == true) {
+          buffer.write(''' class="inherited"''');
         }
+        buffer.write('''>''');
+        buffer.write(context7.linkedName.toString());
+        buffer.write('''</li>''');
       }
+    }
+    buffer.writeln();
+    if (context1.hasPublicInstanceMethods == true) {
       buffer.writeln();
-      if (context1.hasPublicInstanceMethods == true) {
+      buffer.write('''
+    <li class="section-title''');
+      if (context1.publicInheritedInstanceMethods == true) {
+        buffer.write(''' inherited''');
+      }
+      buffer.write('''"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#instance-methods">Methods</a></li>''');
+      var context8 = context1.publicInstanceMethodsSorted;
+      for (var context9 in context8) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title''');
-        if (context1.publicInheritedInstanceMethods == true) {
-          buffer.write(''' inherited''');
-        }
-        buffer.write('''"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#instance-methods">Methods</a></li>''');
-        var context8 = context1.publicInstanceMethodsSorted;
-        if (context8 != null) {
-          for (var context9 in context8) {
-            buffer.writeln();
-            buffer.write('''
     <li''');
-            if (context9.isInherited == true) {
-              buffer.write(''' class="inherited"''');
-            }
-            buffer.write('''>''');
-            buffer.write(context9.linkedName.toString());
-            buffer.write('''</li>''');
-          }
+        if (context9.isInherited == true) {
+          buffer.write(''' class="inherited"''');
         }
+        buffer.write('''>''');
+        buffer.write(context9.linkedName.toString());
+        buffer.write('''</li>''');
       }
+    }
+    buffer.writeln();
+    if (context1.hasPublicInstanceOperators == true) {
       buffer.writeln();
-      if (context1.hasPublicInstanceOperators == true) {
+      buffer.write('''
+    <li class="section-title''');
+      if (context1.publicInheritedInstanceOperators == true) {
+        buffer.write(''' inherited''');
+      }
+      buffer.write('''"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#operators">Operators</a></li>''');
+      var context10 = context1.publicInstanceOperatorsSorted;
+      for (var context11 in context10) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title''');
-        if (context1.publicInheritedInstanceOperators == true) {
-          buffer.write(''' inherited''');
-        }
-        buffer.write('''"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#operators">Operators</a></li>''');
-        var context10 = context1.publicInstanceOperatorsSorted;
-        if (context10 != null) {
-          for (var context11 in context10) {
-            buffer.writeln();
-            buffer.write('''
     <li''');
-            if (context11.isInherited == true) {
-              buffer.write(''' class="inherited"''');
-            }
-            buffer.write('''>''');
-            buffer.write(context11.linkedName.toString());
-            buffer.write('''</li>''');
-          }
+        if (context11.isInherited == true) {
+          buffer.write(''' class="inherited"''');
         }
+        buffer.write('''>''');
+        buffer.write(context11.linkedName.toString());
+        buffer.write('''</li>''');
       }
     }
-    buffer.writeln();
-    if (context1.isExtension == true) {
-      if (context1.hasPublicInstanceFields == true) {
-        buffer.writeln();
-        buffer.write('''
+  }
+  buffer.writeln();
+  if (context1.isExtension == true) {
+    if (context1.hasPublicInstanceFields == true) {
+      buffer.writeln();
+      buffer.write('''
     <li class="section-title"> <a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#instance-properties">Properties</a>
+      buffer.write(context1.href?.toString());
+      buffer.write('''#instance-properties">Properties</a>
     </li>''');
-        var context12 = context1.publicInstanceFieldsSorted;
-        if (context12 != null) {
-          for (var context13 in context12) {
-            buffer.writeln();
-            buffer.write('''
+      var context12 = context1.publicInstanceFieldsSorted;
+      for (var context13 in context12) {
+        buffer.writeln();
+        buffer.write('''
     <li>''');
-            buffer.write(context13.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context13.linkedName.toString());
+        buffer.write('''</li>''');
       }
+    }
+    buffer.writeln();
+    if (context1.hasPublicInstanceMethods == true) {
       buffer.writeln();
-      if (context1.hasPublicInstanceMethods == true) {
+      buffer.write('''
+    <li class="section-title"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#instance-methods">Methods</a></li>''');
+      var context14 = context1.publicInstanceMethodsSorted;
+      for (var context15 in context14) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#instance-methods">Methods</a></li>''');
-        var context14 = context1.publicInstanceMethodsSorted;
-        if (context14 != null) {
-          for (var context15 in context14) {
-            buffer.writeln();
-            buffer.write('''
     <li>''');
-            buffer.write(context15.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context15.linkedName.toString());
+        buffer.write('''</li>''');
       }
+    }
+    buffer.writeln();
+    if (context1.hasPublicInstanceOperators == true) {
       buffer.writeln();
-      if (context1.hasPublicInstanceOperators == true) {
+      buffer.write('''
+    <li class="section-title"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#operators">Operators</a></li>''');
+      var context16 = context1.publicInstanceOperatorsSorted;
+      for (var context17 in context16) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#operators">Operators</a></li>''');
-        var context16 = context1.publicInstanceOperatorsSorted;
-        if (context16 != null) {
-          for (var context17 in context16) {
-            buffer.writeln();
-            buffer.write('''
     <li>''');
-            buffer.write(context17.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context17.linkedName.toString());
+        buffer.write('''</li>''');
       }
     }
-    buffer.writeln();
-    if (context1.isClassOrExtension == true) {
-      if (context1.hasPublicVariableStaticFields == true) {
+  }
+  buffer.writeln();
+  if (context1.isClassOrExtension == true) {
+    if (context1.hasPublicVariableStaticFields == true) {
+      buffer.writeln();
+      buffer.write('''
+    <li class="section-title"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#static-properties">Static properties</a></li>''');
+      var context18 = context1.publicVariableStaticFieldsSorted;
+      for (var context19 in context18) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#static-properties">Static properties</a></li>''');
-        var context18 = context1.publicVariableStaticFieldsSorted;
-        if (context18 != null) {
-          for (var context19 in context18) {
-            buffer.writeln();
-            buffer.write('''
     <li>''');
-            buffer.write(context19.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context19.linkedName.toString());
+        buffer.write('''</li>''');
       }
+    }
+    buffer.writeln();
+    if (context1.hasPublicStaticMethods == true) {
       buffer.writeln();
-      if (context1.hasPublicStaticMethods == true) {
+      buffer.write('''
+    <li class="section-title"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#static-methods">Static methods</a></li>''');
+      var context20 = context1.publicStaticMethodsSorted;
+      for (var context21 in context20) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#static-methods">Static methods</a></li>''');
-        var context20 = context1.publicStaticMethodsSorted;
-        if (context20 != null) {
-          for (var context21 in context20) {
-            buffer.writeln();
-            buffer.write('''
     <li>''');
-            buffer.write(context21.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context21.linkedName.toString());
+        buffer.write('''</li>''');
       }
+    }
+    buffer.writeln();
+    if (context1.hasPublicConstantFields == true) {
       buffer.writeln();
-      if (context1.hasPublicConstantFields == true) {
+      buffer.write('''
+    <li class="section-title"><a href="''');
+      buffer.write(context1.href?.toString());
+      buffer.write('''#constants">Constants</a></li>''');
+      var context22 = context1.publicConstantFieldsSorted;
+      for (var context23 in context22) {
         buffer.writeln();
         buffer.write('''
-    <li class="section-title"><a href="''');
-        buffer.write(context1.href.toString());
-        buffer.write('''#constants">Constants</a></li>''');
-        var context22 = context1.publicConstantFieldsSorted;
-        if (context22 != null) {
-          for (var context23 in context22) {
-            buffer.writeln();
-            buffer.write('''
     <li>''');
-            buffer.write(context23.linkedName.toString());
-            buffer.write('''</li>''');
-          }
-        }
+        buffer.write(context23.linkedName.toString());
+        buffer.write('''</li>''');
       }
     }
   }
@@ -9335,167 +8802,147 @@ String renderSidebarForLibrary<T extends _i18.Documentable>(
   final buffer = StringBuffer();
   buffer.write('''<ol>''');
   var context1 = context0.library;
-  if (context1 != null) {
-    if (context1.hasPublicClasses == true) {
+  if (context1.hasPublicClasses == true) {
+    buffer.writeln();
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#classes">Classes</a></li>''');
+    var context2 = context1.publicClassesSorted;
+    for (var context3 in context2) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#classes">Classes</a></li>''');
-      var context2 = context1.publicClassesSorted;
-      if (context2 != null) {
-        for (var context3 in context2) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context3.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context3.linkedName.toString());
+      buffer.write('''</li>''');
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicExtensions == true) {
     buffer.writeln();
-    if (context1.hasPublicExtensions == true) {
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#extensions">Extensions</a></li>''');
+    var context4 = context1.publicExtensionsSorted;
+    for (var context5 in context4) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#extensions">Extensions</a></li>''');
-      var context4 = context1.publicExtensionsSorted;
-      if (context4 != null) {
-        for (var context5 in context4) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context5.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context5.linkedName.toString());
+      buffer.write('''</li>''');
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicMixins == true) {
     buffer.writeln();
-    if (context1.hasPublicMixins == true) {
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#mixins">Mixins</a></li>''');
+    var context6 = context1.publicMixinsSorted;
+    for (var context7 in context6) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#mixins">Mixins</a></li>''');
-      var context6 = context1.publicMixinsSorted;
-      if (context6 != null) {
-        for (var context7 in context6) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context7.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context7.linkedName.toString());
+      buffer.write('''</li>''');
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicConstants == true) {
     buffer.writeln();
-    if (context1.hasPublicConstants == true) {
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#constants">Constants</a></li>''');
+    var context8 = context1.publicConstantsSorted;
+    for (var context9 in context8) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#constants">Constants</a></li>''');
-      var context8 = context1.publicConstantsSorted;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context9.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context9.linkedName.toString());
+      buffer.write('''</li>''');
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicProperties == true) {
     buffer.writeln();
-    if (context1.hasPublicProperties == true) {
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#properties">Properties</a></li>''');
+    var context10 = context1.publicPropertiesSorted;
+    for (var context11 in context10) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#properties">Properties</a></li>''');
-      var context10 = context1.publicPropertiesSorted;
-      if (context10 != null) {
-        for (var context11 in context10) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context11.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context11.linkedName.toString());
+      buffer.write('''</li>''');
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicFunctions == true) {
     buffer.writeln();
-    if (context1.hasPublicFunctions == true) {
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#functions">Functions</a></li>''');
+    var context12 = context1.publicFunctionsSorted;
+    for (var context13 in context12) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#functions">Functions</a></li>''');
-      var context12 = context1.publicFunctionsSorted;
-      if (context12 != null) {
-        for (var context13 in context12) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context13.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context13.linkedName.toString());
+      buffer.write('''</li>''');
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicEnums == true) {
     buffer.writeln();
-    if (context1.hasPublicEnums == true) {
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#enums">Enums</a></li>''');
+    var context14 = context1.publicEnumsSorted;
+    for (var context15 in context14) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#enums">Enums</a></li>''');
-      var context14 = context1.publicEnumsSorted;
-      if (context14 != null) {
-        for (var context15 in context14) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context15.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context15.linkedName.toString());
+      buffer.write('''</li>''');
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicTypedefs == true) {
     buffer.writeln();
-    if (context1.hasPublicTypedefs == true) {
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#typedefs">Typedefs</a></li>''');
+    var context16 = context1.publicTypedefsSorted;
+    for (var context17 in context16) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#typedefs">Typedefs</a></li>''');
-      var context16 = context1.publicTypedefsSorted;
-      if (context16 != null) {
-        for (var context17 in context16) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context17.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context17.linkedName.toString());
+      buffer.write('''</li>''');
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicExceptions == true) {
     buffer.writeln();
-    if (context1.hasPublicExceptions == true) {
+    buffer.write('''
+  <li class="section-title"><a href="''');
+    buffer.write(context1.href?.toString());
+    buffer.write('''#exceptions">Exceptions</a></li>''');
+    var context18 = context1.publicExceptionsSorted;
+    for (var context19 in context18) {
       buffer.writeln();
       buffer.write('''
-  <li class="section-title"><a href="''');
-      buffer.write(context1.href.toString());
-      buffer.write('''#exceptions">Exceptions</a></li>''');
-      var context18 = context1.publicExceptionsSorted;
-      if (context18 != null) {
-        for (var context19 in context18) {
-          buffer.writeln();
-          buffer.write('''
   <li>''');
-          buffer.write(context19.linkedName.toString());
-          buffer.write('''</li>''');
-        }
-      }
+      buffer.write(context19.linkedName.toString());
+      buffer.write('''</li>''');
     }
   }
   buffer.writeln();
@@ -9514,58 +8961,56 @@ String renderTopLevelProperty(_i1.TopLevelPropertyTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(
-        _renderTopLevelProperty_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-top-level-property">''');
-    buffer.write(context1.name.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(
-        _renderTopLevelProperty_partial_feature_set_2(context1, context0));
-    buffer.write(' ');
-    buffer.write(
-        _renderTopLevelProperty_partial_categorization_3(context1, context0));
-    buffer.write('''</h1></div>
+  buffer
+      .write(_renderTopLevelProperty_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-top-level-property">''');
+  buffer.write(context1.name.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer
+      .write(_renderTopLevelProperty_partial_feature_set_2(context1, context0));
+  buffer.write(' ');
+  buffer.write(
+      _renderTopLevelProperty_partial_categorization_3(context1, context0));
+  buffer.write('''</h1></div>
 ''');
-    if (context1.hasNoGetterSetter == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context1.hasNoGetterSetter == true) {
+    buffer.writeln();
+    buffer.write('''
         <section class="multi-line-signature">
           ''');
-      buffer.write(context1.modelType.linkedName.toString());
-      buffer.write('\n          ');
-      buffer.write(
-          _renderTopLevelProperty_partial_name_summary_4(context1, context0));
-      buffer.write('\n          ');
-      buffer.write(
-          _renderTopLevelProperty_partial_features_5(context1, context0));
-      buffer.writeln();
-      buffer.write('''
+    buffer.write(context1.modelType.linkedName.toString());
+    buffer.write('\n          ');
+    buffer.write(
+        _renderTopLevelProperty_partial_name_summary_4(context1, context0));
+    buffer.write('\n          ');
+    buffer
+        .write(_renderTopLevelProperty_partial_features_5(context1, context0));
+    buffer.writeln();
+    buffer.write('''
         </section>
         ''');
-      buffer.write(
-          _renderTopLevelProperty_partial_documentation_6(context1, context0));
-      buffer.write('\n        ');
-      buffer.write(
-          _renderTopLevelProperty_partial_source_code_7(context1, context0));
-    }
-    buffer.writeln();
-    if (context1.hasExplicitGetter == true) {
-      buffer.write('\n        ');
-      buffer.write(_renderTopLevelProperty_partial_accessor_getter_8(
-          context1, context0));
-    }
-    buffer.writeln();
-    if (context1.hasExplicitSetter == true) {
-      buffer.write('\n        ');
-      buffer.write(_renderTopLevelProperty_partial_accessor_setter_9(
-          context1, context0));
-    }
+    buffer.write(
+        _renderTopLevelProperty_partial_documentation_6(context1, context0));
+    buffer.write('\n        ');
+    buffer.write(
+        _renderTopLevelProperty_partial_source_code_7(context1, context0));
+  }
+  buffer.writeln();
+  if (context1.hasExplicitGetter == true) {
+    buffer.write('\n        ');
+    buffer.write(
+        _renderTopLevelProperty_partial_accessor_getter_8(context1, context0));
+  }
+  buffer.writeln();
+  if (context1.hasExplicitSetter == true) {
+    buffer.write('\n        ');
+    buffer.write(
+        _renderTopLevelProperty_partial_accessor_setter_9(context1, context0));
   }
   buffer.writeln();
   buffer.write('''
@@ -9577,9 +9022,9 @@ String renderTopLevelProperty(_i1.TopLevelPropertyTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForLibrary.toString());
@@ -9626,7 +9071,7 @@ String _renderTopLevelProperty_partial_head_0(
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -9634,14 +9079,12 @@ String _renderTopLevelProperty_partial_head_0(
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -9690,33 +9133,29 @@ String _renderTopLevelProperty_partial_head_0(
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -9729,7 +9168,7 @@ String _renderTopLevelProperty_partial_head_0(
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -9771,11 +9210,9 @@ String _renderTopLevelProperty_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -9788,11 +9225,9 @@ String _renderTopLevelProperty_partial_categorization_3(
   final buffer = StringBuffer();
   if (context1.hasCategoryNames == true) {
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -9838,7 +9273,7 @@ String _renderTopLevelProperty_partial_documentation_6(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -9954,7 +9389,7 @@ String
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context2.documentationAsHtml.toString());
+    buffer.write(context2.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -10000,7 +9435,7 @@ String _renderTopLevelProperty_partial_accessor_setter_9(
         __renderTopLevelProperty_partial_accessor_setter_9_partial_name_summary_0(
             context2, context1, context0));
     buffer.write('''<span class="signature">(<wbr>''');
-    buffer.write(context2.linkedParamsNoMetadata.toString());
+    buffer.write(context2.linkedParamsNoMetadata?.toString());
     buffer.write(''')</span>
   ''');
     buffer.write(
@@ -10073,7 +9508,7 @@ String
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context2.documentationAsHtml.toString());
+    buffer.write(context2.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -10114,33 +9549,29 @@ String _renderTopLevelProperty_partial_search_sidebar_10(
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -10153,7 +9584,7 @@ String _renderTopLevelProperty_partial_search_sidebar_10(
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -10226,42 +9657,35 @@ String renderTypedef(_i1.TypedefTemplateData context0) {
 
   <div id="dartdoc-main-content" class="main-content">''');
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
       <div>''');
-    buffer.write(_renderTypedef_partial_source_link_1(context1, context0));
-    buffer.write('''<h1><span class="kind-typedef">''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write('''</span> ''');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write(' ');
-    buffer.write(_renderTypedef_partial_feature_set_2(context1, context0));
-    buffer.write(' ');
-    buffer.write(_renderTypedef_partial_categorization_3(context1, context0));
-    buffer.write('''</h1></div>''');
-  }
+  buffer.write(_renderTypedef_partial_source_link_1(context1, context0));
+  buffer.write('''<h1><span class="kind-typedef">''');
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write('''</span> ''');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write(' ');
+  buffer.write(_renderTypedef_partial_feature_set_2(context1, context0));
+  buffer.write(' ');
+  buffer.write(_renderTypedef_partial_categorization_3(context1, context0));
+  buffer.write('''</h1></div>''');
   buffer.writeln();
   buffer.write('''
 
     <section class="multi-line-signature">''');
   var context2 = context0.typeDef;
-  if (context2 != null) {
-    buffer.write('\n        ');
-    buffer
-        .write(_renderTypedef_partial_typedef_multiline_4(context2, context0));
-  }
+  buffer.write('\n        ');
+  buffer.write(_renderTypedef_partial_typedef_multiline_4(context2, context0));
   buffer.writeln();
   buffer.write('''
     </section>
 ''');
   var context3 = context0.typeDef;
-  if (context3 != null) {
-    buffer.write('\n    ');
-    buffer.write(_renderTypedef_partial_documentation_5(context3, context0));
-    buffer.write('\n    ');
-    buffer.write(_renderTypedef_partial_source_code_6(context3, context0));
-  }
+  buffer.write('\n    ');
+  buffer.write(_renderTypedef_partial_documentation_5(context3, context0));
+  buffer.write('\n    ');
+  buffer.write(_renderTypedef_partial_source_code_6(context3, context0));
   buffer.writeln();
   buffer.write('''
 
@@ -10273,9 +9697,9 @@ String renderTypedef(_i1.TypedefTemplateData context0) {
   buffer.writeln();
   buffer.write('''
     <h5>''');
-  buffer.writeEscaped(context0.parent.name.toString());
+  buffer.writeEscaped(context0.parent!.name.toString());
   buffer.write(' ');
-  buffer.writeEscaped(context0.parent.kind.toString());
+  buffer.writeEscaped(context0.parent!.kind.toString());
   buffer.write('''</h5>
     ''');
   buffer.write(context0.sidebarForLibrary.toString());
@@ -10321,7 +9745,7 @@ String _renderTypedef_partial_head_0(_i1.TypedefTemplateData context0) {
     buffer.writeln();
     buffer.write('''
   <link rel="canonical" href="''');
-    buffer.write(context0.relCanonicalPrefix.toString());
+    buffer.write(context0.relCanonicalPrefix?.toString());
     buffer.write('''/''');
     buffer.write(context0.bareHref.toString());
     buffer.write('''">''');
@@ -10329,14 +9753,12 @@ String _renderTypedef_partial_head_0(_i1.TypedefTemplateData context0) {
   buffer.writeln();
   if (context0.useBaseHref == true) {
     var context2 = context0.htmlBase;
-    if (context2 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
   <!-- required because all the links are pseudo-absolute -->
   <base href="''');
-      buffer.write(context0.htmlBase.toString());
-      buffer.write('''">''');
-    }
+    buffer.write(context0.htmlBase.toString());
+    buffer.write('''">''');
   }
   buffer.write('\n\n  ');
   buffer.writeln();
@@ -10385,33 +9807,29 @@ String _renderTypedef_partial_head_0(_i1.TypedefTemplateData context0) {
   <button id="sidenav-left-toggle" type="button">&nbsp;</button>
   <ol class="breadcrumbs gt-separated dark hidden-xs">''');
   var context3 = context0.navLinks;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context5 = context0.navLinksWithGenerics;
-  if (context5 != null) {
-    for (var context6 in context5) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context6 in context5) {
+    buffer.writeln();
+    buffer.write('''
     <li><a href="''');
-      buffer.write(context6.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context6.name.toString());
-      if (context6.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context6.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context6.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context6.name.toString());
+    if (context6.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context6.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -10424,7 +9842,7 @@ String _renderTypedef_partial_head_0(_i1.TypedefTemplateData context0) {
     buffer.writeln();
     buffer.write('''
     <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -10466,11 +9884,9 @@ String _renderTypedef_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -10483,11 +9899,9 @@ String _renderTypedef_partial_categorization_3(
   final buffer = StringBuffer();
   if (context1.hasCategoryNames == true) {
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -10500,43 +9914,39 @@ String _renderTypedef_partial_typedef_multiline_4(
   final buffer = StringBuffer();
   if (context1.isCallable == true) {
     var context2 = context1.asCallable;
-    if (context2 != null) {
-      if (context2.hasAnnotations == true) {
-        buffer.writeln();
-        buffer.write('''
+    if (context2.hasAnnotations == true) {
+      buffer.writeln();
+      buffer.write('''
     <div>
       <ol class="annotation-list">''');
-        var context3 = context2.annotations;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
-      <li>''');
-            buffer.write(context4.linkedNameWithParameters.toString());
-            buffer.write('''</li>''');
-          }
-        }
+      var context3 = context2.annotations;
+      for (var context4 in context3) {
         buffer.writeln();
         buffer.write('''
+      <li>''');
+        buffer.write(context4.linkedNameWithParameters.toString());
+        buffer.write('''</li>''');
+      }
+      buffer.writeln();
+      buffer.write('''
     </ol>
     </div>''');
-      }
-      if (context2.isConst == true) {
-        buffer.write('''const ''');
-      }
-      buffer.write('''<span class="name ''');
-      if (context2.isDeprecated == true) {
-        buffer.write('''deprecated''');
-      }
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</span>''');
-      buffer.write(context2.linkedGenericParameters.toString());
-      buffer.write(''' =
-     <span class="returntype">''');
-      buffer.write(context2.modelType.linkedName.toString());
-      buffer.write('''</span>''');
     }
+    if (context2.isConst == true) {
+      buffer.write('''const ''');
+    }
+    buffer.write('''<span class="name ''');
+    if (context2.isDeprecated == true) {
+      buffer.write('''deprecated''');
+    }
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</span>''');
+    buffer.write(context2.linkedGenericParameters.toString());
+    buffer.write(''' =
+     <span class="returntype">''');
+    buffer.write(context2.modelType.linkedName.toString());
+    buffer.write('''</span>''');
   }
   if (context1.isCallable != true) {
     buffer.write('\n  ');
@@ -10558,14 +9968,12 @@ String __renderTypedef_partial_typedef_multiline_4_partial_type_multiline_0(
 <div>
   <ol class="annotation-list">''');
     var context2 = context1.annotations;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write('''
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write('''
     <li>''');
-        buffer.write(context3.linkedNameWithParameters.toString());
-        buffer.write('''</li>''');
-      }
+      buffer.write(context3.linkedNameWithParameters.toString());
+      buffer.write('''</li>''');
     }
     buffer.writeln();
     buffer.write('''
@@ -10611,7 +10019,7 @@ String _renderTypedef_partial_documentation_5(
     buffer.write('''
 <section class="desc markdown">
   ''');
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
     buffer.writeln();
     buffer.write('''
 </section>''');
@@ -10650,33 +10058,29 @@ String _renderTypedef_partial_search_sidebar_7(
 
 <ol class="breadcrumbs gt-separated dark hidden-l" id="sidebar-nav">''');
   var context1 = context0.navLinks;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context2 in context1) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context2.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write('''</a></li>''');
-    }
+    buffer.write(context2.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write('''</a></li>''');
   }
   var context3 = context0.navLinksWithGenerics;
-  if (context3 != null) {
-    for (var context4 in context3) {
-      buffer.writeln();
-      buffer.write('''
+  for (var context4 in context3) {
+    buffer.writeln();
+    buffer.write('''
   <li><a href="''');
-      buffer.write(context4.href.toString());
-      buffer.write('''">''');
-      buffer.writeEscaped(context4.name.toString());
-      if (context4.hasGenericParameters == true) {
-        buffer.write('''<span class="signature">''');
-        buffer.write(context4.genericParameters.toString());
-        buffer.write('''</span>''');
-      }
-      buffer.write('''</a></li>''');
+    buffer.write(context4.href?.toString());
+    buffer.write('''">''');
+    buffer.writeEscaped(context4.name.toString());
+    if (context4.hasGenericParameters == true) {
+      buffer.write('''<span class="signature">''');
+      buffer.write(context4.genericParameters.toString());
+      buffer.write('''</span>''');
     }
+    buffer.write('''</a></li>''');
   }
   if (context0.hasHomepage != true) {
     buffer.writeln();
@@ -10689,7 +10093,7 @@ String _renderTypedef_partial_search_sidebar_7(
     buffer.writeln();
     buffer.write('''
   <li><a href="''');
-    buffer.write(context0.homepage.toString());
+    buffer.write(context0.homepage?.toString());
     buffer.write('''">''');
     buffer.write(context0.layoutTitle.toString());
     buffer.write('''</a></li>''');
@@ -10754,7 +10158,7 @@ String _renderTypedef_partial_footer_8(_i1.TypedefTemplateData context0) {
 }
 
 extension on StringBuffer {
-  void writeEscaped(String value) {
-    write(_i19.htmlEscape.convert(value));
+  void writeEscaped(String? value) {
+    write(_i19.htmlEscape.convert(value ?? ''));
   }
 }
diff --git a/lib/src/generator/templates.aot_renderers_for_md.dart b/lib/src/generator/templates.aot_renderers_for_md.dart
index 7aef7ce29d..70090700d1 100644
--- a/lib/src/generator/templates.aot_renderers_for_md.dart
+++ b/lib/src/generator/templates.aot_renderers_for_md.dart
@@ -7,7 +7,6 @@
 // the variable is not used; generally when the section is checking if a
 // non-bool, non-Iterable field is non-null.
 // ignore_for_file: unused_local_variable
-// @dart=2.9
 // ignore_for_file: non_constant_identifier_names, unnecessary_string_escapes
 
 import 'dart:convert' as _i19;
@@ -36,158 +35,138 @@ String renderCategory(_i1.CategoryTemplateData context0) {
   buffer.write(_renderCategory_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.writeEscaped(context1.name.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderCategory_partial_documentation_1(context1, context0));
+  buffer.writeEscaped(context1.name.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderCategory_partial_documentation_1(context1, context0));
+  buffer.writeln();
+  if (context1.hasPublicLibraries == true) {
     buffer.writeln();
-    if (context1.hasPublicLibraries == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Libraries
 ''');
-      var context2 = context1.publicLibrariesSorted;
-      if (context2 != null) {
-        for (var context3 in context2) {
-          buffer.writeln();
-          buffer.write(
-              _renderCategory_partial_library_2(context3, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context2 = context1.publicLibrariesSorted;
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_library_2(context3, context1, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicClasses == true) {
     buffer.writeln();
-    if (context1.hasPublicClasses == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Classes
 ''');
-      var context4 = context1.publicClassesSorted;
-      if (context4 != null) {
-        for (var context5 in context4) {
-          buffer.writeln();
-          buffer.write(_renderCategory_partial_container_3(
-              context5, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context4 = context1.publicClassesSorted;
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_container_3(context5, context1, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicMixins == true) {
     buffer.writeln();
-    if (context1.hasPublicMixins == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Mixins
 ''');
-      var context6 = context1.publicMixinsSorted;
-      if (context6 != null) {
-        for (var context7 in context6) {
-          buffer.writeln();
-          buffer.write(_renderCategory_partial_container_3(
-              context7, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context6 = context1.publicMixinsSorted;
+    for (var context7 in context6) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_container_3(context7, context1, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicConstants == true) {
     buffer.writeln();
-    if (context1.hasPublicConstants == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Constants
 ''');
-      var context8 = context1.publicConstantsSorted;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.writeln();
-          buffer.write(
-              _renderCategory_partial_constant_4(context9, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context8 = context1.publicConstantsSorted;
+    for (var context9 in context8) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_constant_4(context9, context1, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicProperties == true) {
     buffer.writeln();
-    if (context1.hasPublicProperties == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Properties
 ''');
-      var context10 = context1.publicPropertiesSorted;
-      if (context10 != null) {
-        for (var context11 in context10) {
-          buffer.writeln();
-          buffer.write(_renderCategory_partial_property_5(
-              context11, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context10 = context1.publicPropertiesSorted;
+    for (var context11 in context10) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_property_5(context11, context1, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicFunctions == true) {
     buffer.writeln();
-    if (context1.hasPublicFunctions == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Functions
 ''');
-      var context12 = context1.publicFunctionsSorted;
-      if (context12 != null) {
-        for (var context13 in context12) {
-          buffer.writeln();
-          buffer.write(_renderCategory_partial_callable_6(
-              context13, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context12 = context1.publicFunctionsSorted;
+    for (var context13 in context12) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_callable_6(context13, context1, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicEnums == true) {
     buffer.writeln();
-    if (context1.hasPublicEnums == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Enums
 ''');
-      var context14 = context1.publicEnumsSorted;
-      if (context14 != null) {
-        for (var context15 in context14) {
-          buffer.writeln();
-          buffer.write(_renderCategory_partial_container_3(
-              context15, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context14 = context1.publicEnumsSorted;
+    for (var context15 in context14) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_container_3(context15, context1, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicTypedefs == true) {
     buffer.writeln();
-    if (context1.hasPublicTypedefs == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Typedefs
 ''');
-      var context16 = context1.publicTypedefsSorted;
-      if (context16 != null) {
-        for (var context17 in context16) {
-          buffer.writeln();
-          buffer.write(
-              _renderCategory_partial_typedef_7(context17, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context16 = context1.publicTypedefsSorted;
+    for (var context17 in context16) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_typedef_7(context17, context1, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context1.hasPublicExceptions == true) {
     buffer.writeln();
-    if (context1.hasPublicExceptions == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Exceptions / Errors
 ''');
-      var context18 = context1.publicExceptionsSorted;
-      if (context18 != null) {
-        for (var context19 in context18) {
-          buffer.writeln();
-          buffer.write(_renderCategory_partial_container_3(
-              context19, context1, context0));
-          buffer.writeln();
-        }
-      }
+    var context18 = context1.publicExceptionsSorted;
+    for (var context19 in context18) {
+      buffer.writeln();
+      buffer.write(
+          _renderCategory_partial_container_3(context19, context1, context0));
+      buffer.writeln();
     }
   }
   buffer.write('\n\n');
@@ -210,7 +189,7 @@ String _renderCategory_partial_documentation_1(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -224,7 +203,7 @@ String _renderCategory_partial_library_2(_i3.Library context2,
   buffer.write(context2.linkedName.toString());
   if (context2.isDocumented == true) {
     buffer.writeln();
-    buffer.write(context2.oneLineDoc.toString());
+    buffer.write(context2.oneLineDoc?.toString());
     buffer.write(' ');
     buffer.write(context2.extendedDocLink.toString());
     buffer.writeln();
@@ -244,7 +223,7 @@ String _renderCategory_partial_container_3(_i4.Container context2,
   buffer.write(__renderCategory_partial_container_3_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.writeln();
@@ -262,11 +241,9 @@ String __renderCategory_partial_container_3_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -285,7 +262,7 @@ String _renderCategory_partial_constant_4(_i5.TopLevelVariable context2,
   buffer.write(__renderCategory_partial_constant_4_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -307,11 +284,9 @@ String __renderCategory_partial_constant_4_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -347,7 +322,7 @@ String _renderCategory_partial_property_5(_i5.TopLevelVariable context2,
   buffer.write(__renderCategory_partial_property_5_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -369,11 +344,9 @@ String __renderCategory_partial_property_5_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -403,14 +376,14 @@ String _renderCategory_partial_callable_6(_i6.ModelFunctionTyped context2,
   buffer.write(context2.linkedName.toString());
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''(''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''') ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
   buffer.writeln();
   buffer.write(__renderCategory_partial_callable_6_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -432,11 +405,9 @@ String __renderCategory_partial_callable_6_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -464,26 +435,24 @@ String _renderCategory_partial_typedef_7(_i7.Typedef context2,
   final buffer = StringBuffer();
   if (context2.isCallable == true) {
     var context3 = context2.asCallable;
-    if (context3 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
     ##### ''');
-      buffer.write(context3.linkedName.toString());
-      buffer.write(context3.linkedGenericParameters.toString());
-      buffer.write(''' = ''');
-      buffer.write(context3.modelType.linkedName.toString());
-      buffer.write('\n    ');
-      buffer.write(__renderCategory_partial_typedef_7_partial_categorization_0(
-          context3, context2, context1, context0));
-      buffer.write('\n\n    ');
-      buffer.write(context3.oneLineDoc.toString());
-      buffer.write(' ');
-      buffer.write(context3.extendedDocLink.toString());
-      buffer.write('  ');
-      buffer.write('\n    ');
-      buffer.write(__renderCategory_partial_typedef_7_partial_features_1(
-          context3, context2, context1, context0));
-    }
+    buffer.write(context3.linkedName.toString());
+    buffer.write(context3.linkedGenericParameters.toString());
+    buffer.write(''' = ''');
+    buffer.write(context3.modelType.linkedName.toString());
+    buffer.write('\n    ');
+    buffer.write(__renderCategory_partial_typedef_7_partial_categorization_0(
+        context3, context2, context1, context0));
+    buffer.write('\n\n    ');
+    buffer.write(context3.oneLineDoc?.toString());
+    buffer.write(' ');
+    buffer.write(context3.extendedDocLink.toString());
+    buffer.write('  ');
+    buffer.write('\n    ');
+    buffer.write(__renderCategory_partial_typedef_7_partial_features_1(
+        context3, context2, context1, context0));
   }
   if (context2.isCallable != true) {
     buffer.write('\n  ');
@@ -506,11 +475,9 @@ String __renderCategory_partial_typedef_7_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.writeln();
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -547,7 +514,7 @@ String __renderCategory_partial_typedef_7_partial_type_2(_i7.Typedef context2,
       ___renderCategory_partial_typedef_7_partial_type_2_partial_categorization_0(
           context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -571,11 +538,9 @@ String
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -614,253 +579,225 @@ String renderClass(_i1.ClassTemplateData context0) {
   buffer.write(_renderClass_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderClass_partial_source_link_1(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderClass_partial_categorization_2(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderClass_partial_feature_set_3(context1, context0));
-  }
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderClass_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderClass_partial_categorization_2(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderClass_partial_feature_set_3(context1, context0));
   buffer.writeln();
   var context2 = context0.clazz;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer.write(_renderClass_partial_documentation_4(context2, context0));
-    buffer.writeln();
-    if (context2.hasModifiers == true) {
-      if (context2.hasPublicSuperChainReversed == true) {
-        buffer.writeln();
-        buffer.write('''
+  buffer.writeln();
+  buffer.write(_renderClass_partial_documentation_4(context2, context0));
+  buffer.writeln();
+  if (context2.hasModifiers == true) {
+    if (context2.hasPublicSuperChainReversed == true) {
+      buffer.writeln();
+      buffer.write('''
 **Inheritance**
 
 - ''');
-        buffer.write(context0.linkedObjectType.toString());
-        var context3 = context2.publicSuperChainReversed;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
-- ''');
-            buffer.write(context4.linkedName.toString());
-          }
-        }
+      buffer.write(context0.linkedObjectType.toString());
+      var context3 = context2.publicSuperChainReversed;
+      for (var context4 in context3) {
         buffer.writeln();
         buffer.write('''
 - ''');
-        buffer.write(context2.name.toString());
+        buffer.write(context4.linkedName.toString());
       }
       buffer.writeln();
-      if (context2.hasPublicInterfaces == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
+- ''');
+      buffer.write(context2.name.toString());
+    }
+    buffer.writeln();
+    if (context2.hasPublicInterfaces == true) {
+      buffer.writeln();
+      buffer.write('''
 **Implemented types**
 ''');
-        var context5 = context2.publicInterfaces;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.writeln();
-            buffer.write('''
+      var context5 = context2.publicInterfaces;
+      for (var context6 in context5) {
+        buffer.writeln();
+        buffer.write('''
 - ''');
-            buffer.write(context6.linkedName.toString());
-          }
-        }
+        buffer.write(context6.linkedName.toString());
       }
+    }
+    buffer.writeln();
+    if (context2.hasPublicMixedInTypes == true) {
       buffer.writeln();
-      if (context2.hasPublicMixedInTypes == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
 **Mixed in types**
 ''');
-        var context7 = context2.publicMixedInTypes;
-        if (context7 != null) {
-          for (var context8 in context7) {
-            buffer.writeln();
-            buffer.write('''
+      var context7 = context2.publicMixedInTypes;
+      for (var context8 in context7) {
+        buffer.writeln();
+        buffer.write('''
 - ''');
-            buffer.write(context8.linkedName.toString());
-          }
-        }
+        buffer.write(context8.linkedName.toString());
       }
+    }
+    buffer.writeln();
+    if (context2.hasPublicImplementors == true) {
       buffer.writeln();
-      if (context2.hasPublicImplementors == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
 **Implementers**
 ''');
-        var context9 = context2.publicImplementorsSorted;
-        if (context9 != null) {
-          for (var context10 in context9) {
-            buffer.writeln();
-            buffer.write('''
+      var context9 = context2.publicImplementorsSorted;
+      for (var context10 in context9) {
+        buffer.writeln();
+        buffer.write('''
 - ''');
-            buffer.write(context10.linkedName.toString());
-          }
-        }
+        buffer.write(context10.linkedName.toString());
       }
+    }
+    buffer.writeln();
+    if (context2.hasPotentiallyApplicableExtensions == true) {
       buffer.writeln();
-      if (context2.hasPotentiallyApplicableExtensions == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
 **Available Extensions**
 ''');
-        var context11 = context2.potentiallyApplicableExtensions;
-        if (context11 != null) {
-          buffer.writeln();
-          buffer.write('''
+      var context11 = context2.potentiallyApplicableExtensions;
+      if (context11 != null) {
+        buffer.writeln();
+        buffer.write('''
 - ''');
-          buffer.write(context2.linkedName.toString());
-        }
+        buffer.write(context2.linkedName.toString());
       }
+    }
+    buffer.writeln();
+    if (context2.hasAnnotations == true) {
       buffer.writeln();
-      if (context2.hasAnnotations == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
 **Annotations**
 ''');
-        var context12 = context2.annotations;
-        if (context12 != null) {
-          for (var context13 in context12) {
-            buffer.writeln();
-            buffer.write('''
+      var context12 = context2.annotations;
+      for (var context13 in context12) {
+        buffer.writeln();
+        buffer.write('''
 - ''');
-            buffer.write(context13.linkedNameWithParameters.toString());
-          }
-        }
+        buffer.write(context13.linkedNameWithParameters.toString());
       }
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstructors == true) {
     buffer.writeln();
-    if (context2.hasPublicConstructors == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Constructors
 ''');
-      var context14 = context2.publicConstructorsSorted;
-      if (context14 != null) {
-        for (var context15 in context14) {
-          buffer.writeln();
-          buffer.write(context15.linkedName.toString());
-          buffer.write(''' (''');
-          buffer.write(context15.linkedParams.toString());
-          buffer.write(''')
+    var context14 = context2.publicConstructorsSorted;
+    for (var context15 in context14) {
+      buffer.writeln();
+      buffer.write(context15.linkedName.toString());
+      buffer.write(''' (''');
+      buffer.write(context15.linkedParams.toString());
+      buffer.write(''')
 
 ''');
-          buffer.write(context15.oneLineDoc.toString());
-          buffer.write(' ');
-          buffer.write(context15.extendedDocLink.toString());
-          buffer.write('  ');
-          if (context15.isConst == true) {
-            buffer.write('''_const_''');
-          }
-          buffer.write(' ');
-          if (context15.isFactory == true) {
-            buffer.write('''_factory_''');
-          }
-          buffer.writeln();
-        }
+      buffer.write(context15.oneLineDoc?.toString());
+      buffer.write(' ');
+      buffer.write(context15.extendedDocLink.toString());
+      buffer.write('  ');
+      if (context15.isConst == true) {
+        buffer.write('''_const_''');
+      }
+      buffer.write(' ');
+      if (context15.isFactory == true) {
+        buffer.write('''_factory_''');
       }
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceFields == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Properties
 ''');
-      var context16 = context2.publicInstanceFieldsSorted;
-      if (context16 != null) {
-        for (var context17 in context16) {
-          buffer.writeln();
-          buffer.write(
-              _renderClass_partial_property_5(context17, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context16 = context2.publicInstanceFieldsSorted;
+    for (var context17 in context16) {
+      buffer.writeln();
+      buffer.write(
+          _renderClass_partial_property_5(context17, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Methods
 ''');
-      var context18 = context2.publicInstanceMethodsSorted;
-      if (context18 != null) {
-        for (var context19 in context18) {
-          buffer.writeln();
-          buffer.write(
-              _renderClass_partial_callable_6(context19, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context18 = context2.publicInstanceMethodsSorted;
+    for (var context19 in context18) {
+      buffer.writeln();
+      buffer.write(
+          _renderClass_partial_callable_6(context19, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceOperators == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceOperators == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Operators
 ''');
-      var context20 = context2.publicInstanceOperatorsSorted;
-      if (context20 != null) {
-        for (var context21 in context20) {
-          buffer.writeln();
-          buffer.write(
-              _renderClass_partial_callable_6(context21, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context20 = context2.publicInstanceOperatorsSorted;
+    for (var context21 in context20) {
+      buffer.writeln();
+      buffer.write(
+          _renderClass_partial_callable_6(context21, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicVariableStaticFields == true) {
     buffer.writeln();
-    if (context2.hasPublicVariableStaticFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Static Properties
 ''');
-      var context22 = context2.publicVariableStaticFieldsSorted;
-      if (context22 != null) {
-        for (var context23 in context22) {
-          buffer.writeln();
-          buffer.write(
-              _renderClass_partial_property_5(context23, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context22 = context2.publicVariableStaticFieldsSorted;
+    for (var context23 in context22) {
+      buffer.writeln();
+      buffer.write(
+          _renderClass_partial_property_5(context23, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicStaticMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicStaticMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Static Methods
 ''');
-      var context24 = context2.publicStaticMethodsSorted;
-      if (context24 != null) {
-        for (var context25 in context24) {
-          buffer.writeln();
-          buffer.write(
-              _renderClass_partial_callable_6(context25, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context24 = context2.publicStaticMethodsSorted;
+    for (var context25 in context24) {
+      buffer.writeln();
+      buffer.write(
+          _renderClass_partial_callable_6(context25, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstantFields == true) {
     buffer.writeln();
-    if (context2.hasPublicConstantFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Constants
 ''');
-      var context26 = context2.publicConstantFieldsSorted;
-      if (context26 != null) {
-        for (var context27 in context26) {
-          buffer.writeln();
-          buffer.write(
-              _renderClass_partial_constant_7(context27, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context26 = context2.publicConstantFieldsSorted;
+    for (var context27 in context26) {
+      buffer.writeln();
+      buffer.write(
+          _renderClass_partial_constant_7(context27, context2, context0));
+      buffer.writeln();
     }
   }
   buffer.write('\n\n');
@@ -901,11 +838,9 @@ String _renderClass_partial_categorization_2(
     buffer.write('''
 Categories:''');
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -918,11 +853,9 @@ String _renderClass_partial_feature_set_3(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -935,7 +868,7 @@ String _renderClass_partial_documentation_4(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -955,7 +888,7 @@ String _renderClass_partial_property_5(
   buffer.write(__renderClass_partial_property_5_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -975,11 +908,9 @@ String __renderClass_partial_property_5_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1007,14 +938,14 @@ String _renderClass_partial_callable_6(
   buffer.write(context2.linkedName.toString());
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''(''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''') ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
   buffer.writeln();
   buffer.write(__renderClass_partial_callable_6_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -1034,11 +965,9 @@ String __renderClass_partial_callable_6_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1070,7 +999,7 @@ String _renderClass_partial_constant_7(
   buffer.write(__renderClass_partial_constant_7_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -1090,11 +1019,9 @@ String __renderClass_partial_constant_7_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1131,51 +1058,44 @@ String renderConstructor(_i1.ConstructorTemplateData context0) {
   buffer.write(_renderConstructor_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderConstructor_partial_source_link_1(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderConstructor_partial_feature_set_2(context1, context0));
-  }
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderConstructor_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderConstructor_partial_feature_set_2(context1, context0));
   buffer.writeln();
   var context2 = context0.constructor;
-  if (context2 != null) {
-    if (context2.hasAnnotations == true) {
-      var context3 = context2.annotations;
-      if (context3 != null) {
-        for (var context4 in context3) {
-          buffer.writeln();
-          buffer.write('''
+  if (context2.hasAnnotations == true) {
+    var context3 = context2.annotations;
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write('''
 - ''');
-          buffer.write(context4.linkedNameWithParameters.toString());
-        }
-      }
-    }
-    buffer.writeln();
-    if (context2.isConst == true) {
-      buffer.write('''const''');
-    }
-    buffer.writeln();
-    buffer.write(context2.nameWithGenerics.toString());
-    buffer.write('''(''');
-    if (context2.hasParameters == true) {
-      buffer.write(context2.linkedParamsLines.toString());
+      buffer.write(context4.linkedNameWithParameters.toString());
     }
-    buffer.write(''')
+  }
+  buffer.writeln();
+  if (context2.isConst == true) {
+    buffer.write('''const''');
+  }
+  buffer.writeln();
+  buffer.write(context2.nameWithGenerics.toString());
+  buffer.write('''(''');
+  if (context2.hasParameters == true) {
+    buffer.write(context2.linkedParamsLines.toString());
+  }
+  buffer.write(''')
 
 ''');
-    buffer
-        .write(_renderConstructor_partial_documentation_3(context2, context0));
-    buffer.write('\n\n');
-    buffer.write(_renderConstructor_partial_source_code_4(context2, context0));
-    buffer.writeln();
-  }
+  buffer.write(_renderConstructor_partial_documentation_3(context2, context0));
+  buffer.write('\n\n');
+  buffer.write(_renderConstructor_partial_source_code_4(context2, context0));
+  buffer.writeln();
   buffer.write('\n\n');
   buffer.write(_renderConstructor_partial_footer_5(context0));
   buffer.writeln();
@@ -1211,11 +1131,9 @@ String _renderConstructor_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -1228,7 +1146,7 @@ String _renderConstructor_partial_documentation_3(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -1272,158 +1190,138 @@ String renderEnum(_i1.EnumTemplateData context0) {
   buffer.write(_renderEnum_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.name.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderEnum_partial_source_link_1(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderEnum_partial_feature_set_2(context1, context0));
-  }
+  buffer.write(context1.name.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderEnum_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderEnum_partial_feature_set_2(context1, context0));
   buffer.writeln();
   var context2 = context0.eNum;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer.write(_renderEnum_partial_documentation_3(context2, context0));
-    buffer.writeln();
-    if (context2.hasModifiers == true) {
-      if (context2.hasPublicSuperChainReversed == true) {
-        buffer.writeln();
-        buffer.write('''
+  buffer.writeln();
+  buffer.write(_renderEnum_partial_documentation_3(context2, context0));
+  buffer.writeln();
+  if (context2.hasModifiers == true) {
+    if (context2.hasPublicSuperChainReversed == true) {
+      buffer.writeln();
+      buffer.write('''
 **Inheritance**
 
 - ''');
-        buffer.write(context0.linkedObjectType.toString());
-        var context3 = context2.publicSuperChainReversed;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
-- ''');
-            buffer.write(context4.linkedName.toString());
-          }
-        }
+      buffer.write(context0.linkedObjectType.toString());
+      var context3 = context2.publicSuperChainReversed;
+      for (var context4 in context3) {
         buffer.writeln();
         buffer.write('''
 - ''');
-        buffer.write(context2.name.toString());
+        buffer.write(context4.linkedName.toString());
       }
       buffer.writeln();
-      if (context2.hasAnnotations == true) {
-        buffer.writeln();
-        buffer.write('''
-**Annotations**
-''');
-        var context5 = context2.annotations;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.writeln();
-            buffer.write('''
+      buffer.write('''
 - ''');
-            buffer.write(context6.linkedNameWithParameters.toString());
-          }
-        }
-      }
+      buffer.write(context2.name.toString());
     }
     buffer.writeln();
-    if (context2.hasPublicConstantFields == true) {
+    if (context2.hasAnnotations == true) {
       buffer.writeln();
       buffer.write('''
-## Constants
+**Annotations**
 ''');
-      var context7 = context2.publicConstantFieldsSorted;
-      if (context7 != null) {
-        for (var context8 in context7) {
-          buffer.writeln();
-          buffer.write(
-              _renderEnum_partial_constant_4(context8, context2, context0));
-          buffer.writeln();
-        }
+      var context5 = context2.annotations;
+      for (var context6 in context5) {
+        buffer.writeln();
+        buffer.write('''
+- ''');
+        buffer.write(context6.linkedNameWithParameters.toString());
       }
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstantFields == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceFields == true) {
+    buffer.write('''
+## Constants
+''');
+    var context7 = context2.publicConstantFieldsSorted;
+    for (var context8 in context7) {
       buffer.writeln();
-      buffer.write('''
+      buffer
+          .write(_renderEnum_partial_constant_4(context8, context2, context0));
+      buffer.writeln();
+    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceFields == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Properties
 ''');
-      var context9 = context2.publicInstanceFieldsSorted;
-      if (context9 != null) {
-        for (var context10 in context9) {
-          buffer.writeln();
-          buffer.write(
-              _renderEnum_partial_property_5(context10, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context9 = context2.publicInstanceFieldsSorted;
+    for (var context10 in context9) {
+      buffer.writeln();
+      buffer
+          .write(_renderEnum_partial_property_5(context10, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Methods
 ''');
-      var context11 = context2.publicInstanceMethodsSorted;
-      if (context11 != null) {
-        for (var context12 in context11) {
-          buffer.writeln();
-          buffer.write(
-              _renderEnum_partial_callable_6(context12, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context11 = context2.publicInstanceMethodsSorted;
+    for (var context12 in context11) {
+      buffer.writeln();
+      buffer
+          .write(_renderEnum_partial_callable_6(context12, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceOperators == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceOperators == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Operators
 ''');
-      var context13 = context2.publicInstanceOperatorsSorted;
-      if (context13 != null) {
-        for (var context14 in context13) {
-          buffer.writeln();
-          buffer.write(
-              _renderEnum_partial_callable_6(context14, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context13 = context2.publicInstanceOperatorsSorted;
+    for (var context14 in context13) {
+      buffer.writeln();
+      buffer
+          .write(_renderEnum_partial_callable_6(context14, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicVariableStaticFields == true) {
     buffer.writeln();
-    if (context2.hasPublicVariableStaticFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Static Properties
 ''');
-      var context15 = context2.publicVariableStaticFieldsSorted;
-      if (context15 != null) {
-        for (var context16 in context15) {
-          buffer.writeln();
-          buffer.write(
-              _renderEnum_partial_property_5(context16, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context15 = context2.publicVariableStaticFieldsSorted;
+    for (var context16 in context15) {
+      buffer.writeln();
+      buffer
+          .write(_renderEnum_partial_property_5(context16, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicStaticMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicStaticMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Static Methods
 ''');
-      var context17 = context2.publicStaticMethodsSorted;
-      if (context17 != null) {
-        for (var context18 in context17) {
-          buffer.writeln();
-          buffer.write(
-              _renderEnum_partial_callable_6(context18, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context17 = context2.publicStaticMethodsSorted;
+    for (var context18 in context17) {
+      buffer.writeln();
+      buffer
+          .write(_renderEnum_partial_callable_6(context18, context2, context0));
+      buffer.writeln();
     }
   }
   buffer.write('\n\n');
@@ -1461,11 +1359,9 @@ String _renderEnum_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -1478,7 +1374,7 @@ String _renderEnum_partial_documentation_3(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -1496,7 +1392,7 @@ String _renderEnum_partial_constant_4(
   buffer.write(__renderEnum_partial_constant_4_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -1516,11 +1412,9 @@ String __renderEnum_partial_constant_4_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1554,7 +1448,7 @@ String _renderEnum_partial_property_5(
   buffer.write(__renderEnum_partial_property_5_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -1574,11 +1468,9 @@ String __renderEnum_partial_property_5_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1606,14 +1498,14 @@ String _renderEnum_partial_callable_6(
   buffer.write(context2.linkedName.toString());
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''(''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''') ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
   buffer.writeln();
   buffer.write(__renderEnum_partial_callable_6_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -1633,11 +1525,9 @@ String __renderEnum_partial_callable_6_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1688,127 +1578,109 @@ String renderExtension<T extends _i13.Extension>(
   buffer.write(_renderExtension_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.writeln();
-    buffer.write('''
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.writeln();
+  buffer.write('''
 on ''');
-    var context2 = context1.extendedType;
-    if (context2 != null) {
-      buffer.write(context2.linkedName.toString());
-    }
-    buffer.write('\n\n');
-    buffer.write(_renderExtension_partial_source_link_1(context1, context0));
-    buffer.write('\n\n');
-    buffer.write(_renderExtension_partial_categorization_2(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderExtension_partial_feature_set_3(context1, context0));
-  }
+  var context2 = context1.extendedType;
+  buffer.write(context2.linkedName.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderExtension_partial_source_link_1(context1, context0));
+  buffer.write('\n\n');
+  buffer.write(_renderExtension_partial_categorization_2(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderExtension_partial_feature_set_3(context1, context0));
   buffer.writeln();
   var context3 = context0.extension;
-  if (context3 != null) {
-    buffer.writeln();
-    buffer.write(_renderExtension_partial_documentation_4(context3, context0));
+  buffer.writeln();
+  buffer.write(_renderExtension_partial_documentation_4(context3, context0));
+  buffer.writeln();
+  if (context3.hasPublicInstanceFields == true) {
     buffer.writeln();
-    if (context3.hasPublicInstanceFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Properties
 ''');
-      var context4 = context3.publicInstanceFieldsSorted;
-      if (context4 != null) {
-        for (var context5 in context4) {
-          buffer.writeln();
-          buffer.write(_renderExtension_partial_property_5(
-              context5, context3, context0));
-          buffer.writeln();
-        }
-      }
+    var context4 = context3.publicInstanceFieldsSorted;
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(
+          _renderExtension_partial_property_5(context5, context3, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context3.hasPublicInstanceMethods == true) {
     buffer.writeln();
-    if (context3.hasPublicInstanceMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Methods
 ''');
-      var context6 = context3.publicInstanceMethodsSorted;
-      if (context6 != null) {
-        for (var context7 in context6) {
-          buffer.writeln();
-          buffer.write(_renderExtension_partial_callable_6(
-              context7, context3, context0));
-          buffer.writeln();
-        }
-      }
+    var context6 = context3.publicInstanceMethodsSorted;
+    for (var context7 in context6) {
+      buffer.writeln();
+      buffer.write(
+          _renderExtension_partial_callable_6(context7, context3, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context3.hasPublicInstanceOperators == true) {
     buffer.writeln();
-    if (context3.hasPublicInstanceOperators == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Operators
 ''');
-      var context8 = context3.publicInstanceOperatorsSorted;
-      if (context8 != null) {
-        for (var context9 in context8) {
-          buffer.writeln();
-          buffer.write(_renderExtension_partial_callable_6(
-              context9, context3, context0));
-          buffer.writeln();
-        }
-      }
+    var context8 = context3.publicInstanceOperatorsSorted;
+    for (var context9 in context8) {
+      buffer.writeln();
+      buffer.write(
+          _renderExtension_partial_callable_6(context9, context3, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context3.hasPublicVariableStaticFields == true) {
     buffer.writeln();
-    if (context3.hasPublicVariableStaticFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Static Properties
 ''');
-      var context10 = context3.publicVariableStaticFieldsSorted;
-      if (context10 != null) {
-        for (var context11 in context10) {
-          buffer.writeln();
-          buffer.write(_renderExtension_partial_property_5(
-              context11, context3, context0));
-          buffer.writeln();
-        }
-      }
+    var context10 = context3.publicVariableStaticFieldsSorted;
+    for (var context11 in context10) {
+      buffer.writeln();
+      buffer.write(
+          _renderExtension_partial_property_5(context11, context3, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context3.hasPublicStaticMethods == true) {
     buffer.writeln();
-    if (context3.hasPublicStaticMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Static Methods
 ''');
-      var context12 = context3.publicStaticMethodsSorted;
-      if (context12 != null) {
-        for (var context13 in context12) {
-          buffer.writeln();
-          buffer.write(_renderExtension_partial_callable_6(
-              context13, context3, context0));
-          buffer.writeln();
-        }
-      }
+    var context12 = context3.publicStaticMethodsSorted;
+    for (var context13 in context12) {
+      buffer.writeln();
+      buffer.write(
+          _renderExtension_partial_callable_6(context13, context3, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context3.hasPublicConstantFields == true) {
     buffer.writeln();
-    if (context3.hasPublicConstantFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Constants
 ''');
-      var context14 = context3.publicConstantFieldsSorted;
-      if (context14 != null) {
-        for (var context15 in context14) {
-          buffer.writeln();
-          buffer.write(_renderExtension_partial_constant_7(
-              context15, context3, context0));
-          buffer.writeln();
-        }
-      }
+    var context14 = context3.publicConstantFieldsSorted;
+    for (var context15 in context14) {
+      buffer.writeln();
+      buffer.write(
+          _renderExtension_partial_constant_7(context15, context3, context0));
+      buffer.writeln();
     }
   }
   buffer.write('\n\n');
@@ -1850,11 +1722,9 @@ String _renderExtension_partial_categorization_2<T extends _i13.Extension>(
     buffer.write('''
 Categories:''');
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1867,11 +1737,9 @@ String _renderExtension_partial_feature_set_3<T extends _i13.Extension>(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -1884,7 +1752,7 @@ String _renderExtension_partial_documentation_4<T extends _i13.Extension>(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -1906,7 +1774,7 @@ String _renderExtension_partial_property_5<T extends _i13.Extension>(
   buffer.write(__renderExtension_partial_property_5_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -1927,11 +1795,9 @@ String __renderExtension_partial_property_5_partial_categorization_0<
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -1962,14 +1828,14 @@ String _renderExtension_partial_callable_6<T extends _i13.Extension>(
   buffer.write(context2.linkedName.toString());
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''(''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''') ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
   buffer.writeln();
   buffer.write(__renderExtension_partial_callable_6_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -1990,11 +1856,9 @@ String __renderExtension_partial_callable_6_partial_categorization_0<
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2029,7 +1893,7 @@ String _renderExtension_partial_constant_7<T extends _i13.Extension>(
   buffer.write(__renderExtension_partial_constant_7_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -2050,11 +1914,9 @@ String __renderExtension_partial_constant_7_partial_categorization_0<
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2093,32 +1955,28 @@ String renderFunction(_i1.FunctionTemplateData context0) {
   buffer.write(_renderFunction_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderFunction_partial_source_link_1(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderFunction_partial_categorization_2(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderFunction_partial_feature_set_3(context1, context0));
-  }
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderFunction_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderFunction_partial_categorization_2(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderFunction_partial_feature_set_3(context1, context0));
   buffer.writeln();
   var context2 = context0.function;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer.write(
-        _renderFunction_partial_callable_multiline_4(context2, context0));
-    buffer.write('\n\n');
-    buffer.write(_renderFunction_partial_documentation_5(context2, context0));
-    buffer.write('\n\n');
-    buffer.write(_renderFunction_partial_source_code_6(context2, context0));
-    buffer.writeln();
-  }
+  buffer.writeln();
+  buffer
+      .write(_renderFunction_partial_callable_multiline_4(context2, context0));
+  buffer.write('\n\n');
+  buffer.write(_renderFunction_partial_documentation_5(context2, context0));
+  buffer.write('\n\n');
+  buffer.write(_renderFunction_partial_source_code_6(context2, context0));
+  buffer.writeln();
   buffer.write('\n\n');
   buffer.write(_renderFunction_partial_footer_7(context0));
   buffer.writeln();
@@ -2157,11 +2015,9 @@ String _renderFunction_partial_categorization_2(
     buffer.write('''
 Categories:''');
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2174,11 +2030,9 @@ String _renderFunction_partial_feature_set_3(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -2191,13 +2045,11 @@ String _renderFunction_partial_callable_multiline_4(
   final buffer = StringBuffer();
   if (context1.hasAnnotations == true) {
     var context2 = context1.annotations;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write('''
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write('''
 - ''');
-        buffer.write(context3.linkedNameWithParameters.toString());
-      }
+      buffer.write(context3.linkedNameWithParameters.toString());
     }
   }
   buffer.write('\n\n');
@@ -2240,7 +2092,7 @@ String _renderFunction_partial_documentation_5(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -2288,55 +2140,45 @@ String renderIndex(_i1.PackageTemplateData context0) {
   buffer.writeEscaped(context0.title.toString());
   buffer.writeln();
   var context1 = context0.defaultPackage;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write(_renderIndex_partial_documentation_1(context1, context0));
-  }
+  buffer.writeln();
+  buffer.write(_renderIndex_partial_documentation_1(context1, context0));
   buffer.writeln();
   var context2 = context0.localPackages;
-  if (context2 != null) {
-    for (var context3 in context2) {
-      if (context3.isFirstPackage == true) {
-        buffer.writeln();
-        buffer.write('''
+  for (var context3 in context2) {
+    if (context3.isFirstPackage == true) {
+      buffer.writeln();
+      buffer.write('''
 ## Libraries''');
-      }
-      if (context3.isFirstPackage != true) {
-        buffer.writeln();
-        buffer.write('''
-## ''');
-        buffer.writeEscaped(context3.name.toString());
-      }
+    }
+    if (context3.isFirstPackage != true) {
       buffer.writeln();
-      var context4 = context3.defaultCategory;
-      if (context4 != null) {
-        var context5 = context4.publicLibrariesSorted;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.writeln();
-            buffer.write(_renderIndex_partial_library_2(
-                context6, context4, context3, context0));
-          }
-        }
+      buffer.write('''
+## ''');
+      buffer.writeEscaped(context3.name.toString());
+    }
+    buffer.writeln();
+    var context4 = context3.defaultCategory;
+    if (context4 != null) {
+      var context5 = context4.publicLibrariesSorted;
+      for (var context6 in context5) {
+        buffer.writeln();
+        buffer.write(_renderIndex_partial_library_2(
+            context6, context4, context3, context0));
       }
+    }
+    buffer.writeln();
+    var context7 = context3.categoriesWithPublicLibraries;
+    for (var context8 in context7) {
       buffer.writeln();
-      var context7 = context3.categoriesWithPublicLibraries;
-      if (context7 != null) {
-        for (var context8 in context7) {
-          buffer.writeln();
-          buffer.write('''
+      buffer.write('''
 ### Category ''');
-          buffer.write(context8.categoryLabel.toString());
-          buffer.writeln();
-          var context9 = context8.publicLibrariesSorted;
-          if (context9 != null) {
-            for (var context10 in context9) {
-              buffer.writeln();
-              buffer.write(_renderIndex_partial_library_2(
-                  context10, context8, context3, context0));
-            }
-          }
-        }
+      buffer.write(context8.categoryLabel.toString());
+      buffer.writeln();
+      var context9 = context8.publicLibrariesSorted;
+      for (var context10 in context9) {
+        buffer.writeln();
+        buffer.write(_renderIndex_partial_library_2(
+            context10, context8, context3, context0));
       }
     }
   }
@@ -2360,7 +2202,7 @@ String _renderIndex_partial_documentation_1(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -2377,7 +2219,7 @@ String _renderIndex_partial_library_2(
   buffer.write(context3.linkedName.toString());
   if (context3.isDocumented == true) {
     buffer.writeln();
-    buffer.write(context3.oneLineDoc.toString());
+    buffer.write(context3.oneLineDoc?.toString());
     buffer.write(' ');
     buffer.write(context3.extendedDocLink.toString());
     buffer.writeln();
@@ -2403,222 +2245,164 @@ String renderLibrary(_i1.LibraryTemplateData context0) {
   buffer.write(_renderLibrary_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.name.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderLibrary_partial_source_link_1(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderLibrary_partial_categorization_2(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderLibrary_partial_feature_set_3(context1, context0));
-  }
+  buffer.write(context1.name.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderLibrary_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderLibrary_partial_categorization_2(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderLibrary_partial_feature_set_3(context1, context0));
   buffer.writeln();
   var context2 = context0.library;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer.write(_renderLibrary_partial_documentation_4(context2, context0));
-  }
+  buffer.writeln();
+  buffer.write(_renderLibrary_partial_documentation_4(context2, context0));
   buffer.writeln();
   var context3 = context0.library;
-  if (context3 != null) {
-    if (context3.hasPublicClasses == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context3.hasPublicClasses == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Classes
 ''');
-      var context4 = context3.library;
-      if (context4 != null) {
-        var context5 = context4.publicClassesSorted;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_container_5(
-                context6, context4, context3, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context4 = context3.library;
+    var context5 = context4.publicClassesSorted;
+    for (var context6 in context5) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_container_5(
+          context6, context4, context3, context0));
+      buffer.writeln();
     }
   }
   buffer.writeln();
   var context7 = context0.library;
-  if (context7 != null) {
-    if (context7.hasPublicMixins == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context7.hasPublicMixins == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Mixins
 ''');
-      var context8 = context7.library;
-      if (context8 != null) {
-        var context9 = context8.publicMixinsSorted;
-        if (context9 != null) {
-          for (var context10 in context9) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_container_5(
-                context10, context8, context7, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context8 = context7.library;
+    var context9 = context8.publicMixinsSorted;
+    for (var context10 in context9) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_container_5(
+          context10, context8, context7, context0));
+      buffer.writeln();
     }
   }
   buffer.writeln();
   var context11 = context0.library;
-  if (context11 != null) {
-    if (context11.hasPublicExtensions == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context11.hasPublicExtensions == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Extensions
 ''');
-      var context12 = context11.library;
-      if (context12 != null) {
-        var context13 = context12.publicExtensionsSorted;
-        if (context13 != null) {
-          for (var context14 in context13) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_extension_6(
-                context14, context12, context11, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context12 = context11.library;
+    var context13 = context12.publicExtensionsSorted;
+    for (var context14 in context13) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_extension_6(
+          context14, context12, context11, context0));
+      buffer.writeln();
     }
   }
   buffer.writeln();
   var context15 = context0.library;
-  if (context15 != null) {
-    if (context15.hasPublicConstants == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context15.hasPublicConstants == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Constants
 ''');
-      var context16 = context15.library;
-      if (context16 != null) {
-        var context17 = context16.publicConstantsSorted;
-        if (context17 != null) {
-          for (var context18 in context17) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_constant_7(
-                context18, context16, context15, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context16 = context15.library;
+    var context17 = context16.publicConstantsSorted;
+    for (var context18 in context17) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_constant_7(
+          context18, context16, context15, context0));
+      buffer.writeln();
     }
   }
   buffer.writeln();
   var context19 = context0.library;
-  if (context19 != null) {
-    if (context19.hasPublicProperties == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context19.hasPublicProperties == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Properties
 ''');
-      var context20 = context19.library;
-      if (context20 != null) {
-        var context21 = context20.publicPropertiesSorted;
-        if (context21 != null) {
-          for (var context22 in context21) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_property_8(
-                context22, context20, context19, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context20 = context19.library;
+    var context21 = context20.publicPropertiesSorted;
+    for (var context22 in context21) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_property_8(
+          context22, context20, context19, context0));
+      buffer.writeln();
     }
   }
   buffer.writeln();
   var context23 = context0.library;
-  if (context23 != null) {
-    if (context23.hasPublicFunctions == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context23.hasPublicFunctions == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Functions
 ''');
-      var context24 = context23.library;
-      if (context24 != null) {
-        var context25 = context24.publicFunctionsSorted;
-        if (context25 != null) {
-          for (var context26 in context25) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_callable_9(
-                context26, context24, context23, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context24 = context23.library;
+    var context25 = context24.publicFunctionsSorted;
+    for (var context26 in context25) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_callable_9(
+          context26, context24, context23, context0));
+      buffer.writeln();
     }
   }
   buffer.writeln();
   var context27 = context0.library;
-  if (context27 != null) {
-    if (context27.hasPublicEnums == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context27.hasPublicEnums == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Enums
 ''');
-      var context28 = context27.library;
-      if (context28 != null) {
-        var context29 = context28.publicEnumsSorted;
-        if (context29 != null) {
-          for (var context30 in context29) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_container_5(
-                context30, context28, context27, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context28 = context27.library;
+    var context29 = context28.publicEnumsSorted;
+    for (var context30 in context29) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_container_5(
+          context30, context28, context27, context0));
+      buffer.writeln();
     }
   }
   buffer.writeln();
   var context31 = context0.library;
-  if (context31 != null) {
-    if (context31.hasPublicTypedefs == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context31.hasPublicTypedefs == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Typedefs
 ''');
-      var context32 = context31.library;
-      if (context32 != null) {
-        var context33 = context32.publicTypedefsSorted;
-        if (context33 != null) {
-          for (var context34 in context33) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_typedef_10(
-                context34, context32, context31, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context32 = context31.library;
+    var context33 = context32.publicTypedefsSorted;
+    for (var context34 in context33) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_typedef_10(
+          context34, context32, context31, context0));
+      buffer.writeln();
     }
   }
   buffer.writeln();
   var context35 = context0.library;
-  if (context35 != null) {
-    if (context35.hasPublicExceptions == true) {
-      buffer.writeln();
-      buffer.write('''
+  if (context35.hasPublicExceptions == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Exceptions / Errors
 ''');
-      var context36 = context35.library;
-      if (context36 != null) {
-        var context37 = context36.publicExceptionsSorted;
-        if (context37 != null) {
-          for (var context38 in context37) {
-            buffer.writeln();
-            buffer.write(_renderLibrary_partial_container_5(
-                context38, context36, context35, context0));
-            buffer.writeln();
-          }
-        }
-      }
+    var context36 = context35.library;
+    var context37 = context36.publicExceptionsSorted;
+    for (var context38 in context37) {
+      buffer.writeln();
+      buffer.write(_renderLibrary_partial_container_5(
+          context38, context36, context35, context0));
+      buffer.writeln();
     }
   }
   buffer.write('\n\n');
@@ -2659,11 +2443,9 @@ String _renderLibrary_partial_categorization_2(
     buffer.write('''
 Categories:''');
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2676,11 +2458,9 @@ String _renderLibrary_partial_feature_set_3(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -2693,7 +2473,7 @@ String _renderLibrary_partial_documentation_4(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -2713,7 +2493,7 @@ String _renderLibrary_partial_container_5(
   buffer.write(__renderLibrary_partial_container_5_partial_categorization_0(
       context3, context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.writeln();
@@ -2732,11 +2512,9 @@ String __renderLibrary_partial_container_5_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.writeln();
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2756,7 +2534,7 @@ String _renderLibrary_partial_extension_6(
   buffer.write(__renderLibrary_partial_extension_6_partial_categorization_0(
       context3, context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.writeln();
@@ -2775,11 +2553,9 @@ String __renderLibrary_partial_extension_6_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.writeln();
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2801,7 +2577,7 @@ String _renderLibrary_partial_constant_7(
   buffer.write(__renderLibrary_partial_constant_7_partial_categorization_0(
       context3, context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.write('  ');
@@ -2824,11 +2600,9 @@ String __renderLibrary_partial_constant_7_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.writeln();
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2868,7 +2642,7 @@ String _renderLibrary_partial_property_8(
   buffer.write(__renderLibrary_partial_property_8_partial_categorization_0(
       context3, context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.write('  ');
@@ -2891,11 +2665,9 @@ String __renderLibrary_partial_property_8_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.writeln();
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2929,14 +2701,14 @@ String _renderLibrary_partial_callable_9(
   buffer.write(context3.linkedName.toString());
   buffer.write(context3.linkedGenericParameters.toString());
   buffer.write('''(''');
-  buffer.write(context3.linkedParamsNoMetadata.toString());
+  buffer.write(context3.linkedParamsNoMetadata?.toString());
   buffer.write(''') ''');
   buffer.write(context3.modelType.returnType.linkedName.toString());
   buffer.writeln();
   buffer.write(__renderLibrary_partial_callable_9_partial_categorization_0(
       context3, context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.write('  ');
@@ -2959,11 +2731,9 @@ String __renderLibrary_partial_callable_9_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.writeln();
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(context5!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -2995,26 +2765,24 @@ String _renderLibrary_partial_typedef_10(
   final buffer = StringBuffer();
   if (context3.isCallable == true) {
     var context4 = context3.asCallable;
-    if (context4 != null) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.writeln();
+    buffer.write('''
     ##### ''');
-      buffer.write(context4.linkedName.toString());
-      buffer.write(context4.linkedGenericParameters.toString());
-      buffer.write(''' = ''');
-      buffer.write(context4.modelType.linkedName.toString());
-      buffer.write('\n    ');
-      buffer.write(__renderLibrary_partial_typedef_10_partial_categorization_0(
-          context4, context3, context2, context1, context0));
-      buffer.write('\n\n    ');
-      buffer.write(context4.oneLineDoc.toString());
-      buffer.write(' ');
-      buffer.write(context4.extendedDocLink.toString());
-      buffer.write('  ');
-      buffer.write('\n    ');
-      buffer.write(__renderLibrary_partial_typedef_10_partial_features_1(
-          context4, context3, context2, context1, context0));
-    }
+    buffer.write(context4.linkedName.toString());
+    buffer.write(context4.linkedGenericParameters.toString());
+    buffer.write(''' = ''');
+    buffer.write(context4.modelType.linkedName.toString());
+    buffer.write('\n    ');
+    buffer.write(__renderLibrary_partial_typedef_10_partial_categorization_0(
+        context4, context3, context2, context1, context0));
+    buffer.write('\n\n    ');
+    buffer.write(context4.oneLineDoc?.toString());
+    buffer.write(' ');
+    buffer.write(context4.extendedDocLink.toString());
+    buffer.write('  ');
+    buffer.write('\n    ');
+    buffer.write(__renderLibrary_partial_typedef_10_partial_features_1(
+        context4, context3, context2, context1, context0));
   }
   if (context3.isCallable != true) {
     buffer.write('\n  ');
@@ -3038,11 +2806,9 @@ String __renderLibrary_partial_typedef_10_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context5 = context4.displayedCategories;
-    if (context5 != null) {
-      for (var context6 in context5) {
-        buffer.writeln();
-        buffer.write(context6.categoryLabel.toString());
-      }
+    for (var context6 in context5) {
+      buffer.writeln();
+      buffer.write(context6.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3083,7 +2849,7 @@ String __renderLibrary_partial_typedef_10_partial_type_2(
       ___renderLibrary_partial_typedef_10_partial_type_2_partial_categorization_0(
           context3, context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context3.oneLineDoc.toString());
+  buffer.write(context3.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context3.extendedDocLink.toString());
   buffer.write('  ');
@@ -3108,11 +2874,9 @@ String
     buffer.write('''
 Categories:''');
     var context4 = context3.displayedCategories;
-    if (context4 != null) {
-      for (var context5 in context4) {
-        buffer.writeln();
-        buffer.write(context5.categoryLabel.toString());
-      }
+    for (var context5 in context4) {
+      buffer.writeln();
+      buffer.write(context5.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3152,32 +2916,27 @@ String renderMethod(_i1.MethodTemplateData context0) {
   buffer.write(_renderMethod_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderMethod_partial_source_link_1(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderMethod_partial_feature_set_2(context1, context0));
-  }
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderMethod_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderMethod_partial_feature_set_2(context1, context0));
   buffer.writeln();
   var context2 = context0.method;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer
-        .write(_renderMethod_partial_callable_multiline_3(context2, context0));
-    buffer.writeln();
-    buffer.write(_renderMethod_partial_features_4(context2, context0));
-    buffer.write('\n\n');
-    buffer.write(_renderMethod_partial_documentation_5(context2, context0));
-    buffer.write('\n\n');
-    buffer.write(_renderMethod_partial_source_code_6(context2, context0));
-    buffer.writeln();
-  }
+  buffer.writeln();
+  buffer.write(_renderMethod_partial_callable_multiline_3(context2, context0));
+  buffer.writeln();
+  buffer.write(_renderMethod_partial_features_4(context2, context0));
+  buffer.write('\n\n');
+  buffer.write(_renderMethod_partial_documentation_5(context2, context0));
+  buffer.write('\n\n');
+  buffer.write(_renderMethod_partial_source_code_6(context2, context0));
+  buffer.writeln();
   buffer.write('\n\n');
   buffer.write(_renderMethod_partial_footer_7(context0));
   buffer.writeln();
@@ -3213,11 +2972,9 @@ String _renderMethod_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -3230,13 +2987,11 @@ String _renderMethod_partial_callable_multiline_3(
   final buffer = StringBuffer();
   if (context1.hasAnnotations == true) {
     var context2 = context1.annotations;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write('''
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write('''
 - ''');
-        buffer.write(context3.linkedNameWithParameters.toString());
-      }
+      buffer.write(context3.linkedNameWithParameters.toString());
     }
   }
   buffer.write('\n\n');
@@ -3292,7 +3047,7 @@ String _renderMethod_partial_documentation_5(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -3335,208 +3090,182 @@ String renderMixin(_i1.MixinTemplateData context0) {
   buffer.write(_renderMixin_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderMixin_partial_source_link_1(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderMixin_partial_categorization_2(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderMixin_partial_feature_set_3(context1, context0));
-  }
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderMixin_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderMixin_partial_categorization_2(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderMixin_partial_feature_set_3(context1, context0));
   buffer.writeln();
   var context2 = context0.mixin;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer.write(_renderMixin_partial_documentation_4(context2, context0));
-    buffer.writeln();
-    if (context2.hasModifiers == true) {
-      if (context2.hasPublicSuperclassConstraints == true) {
-        buffer.writeln();
-        buffer.write('''
+  buffer.writeln();
+  buffer.write(_renderMixin_partial_documentation_4(context2, context0));
+  buffer.writeln();
+  if (context2.hasModifiers == true) {
+    if (context2.hasPublicSuperclassConstraints == true) {
+      buffer.writeln();
+      buffer.write('''
 **Superclass Constraints**
 ''');
-        var context3 = context2.publicSuperclassConstraints;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
+      var context3 = context2.publicSuperclassConstraints;
+      for (var context4 in context3) {
+        buffer.writeln();
+        buffer.write('''
 - ''');
-            buffer.write(context4.linkedName.toString());
-          }
-        }
+        buffer.write(context4.linkedName.toString());
       }
+    }
+    buffer.writeln();
+    if (context2.hasPublicSuperChainReversed == true) {
       buffer.writeln();
-      if (context2.hasPublicSuperChainReversed == true) {
-        buffer.writeln();
-        buffer.write('''
+      buffer.write('''
 **Inheritance**
 
 - ''');
-        buffer.write(context0.linkedObjectType.toString());
-        var context5 = context2.publicSuperChainReversed;
-        if (context5 != null) {
-          for (var context6 in context5) {
-            buffer.writeln();
-            buffer.write('''
-- ''');
-            buffer.write(context6.linkedName.toString());
-          }
-        }
+      buffer.write(context0.linkedObjectType.toString());
+      var context5 = context2.publicSuperChainReversed;
+      for (var context6 in context5) {
         buffer.writeln();
         buffer.write('''
 - ''');
-        buffer.write(context2.name.toString());
+        buffer.write(context6.linkedName.toString());
       }
       buffer.writeln();
-      if (context2.hasPublicInterfaces == true) {
-        buffer.writeln();
-        buffer.write('''
-**Implemented types**
-''');
-        var context7 = context2.publicInterfaces;
-        if (context7 != null) {
-          for (var context8 in context7) {
-            buffer.writeln();
-            buffer.write('''
+      buffer.write('''
 - ''');
-            buffer.write(context8.linkedName.toString());
-          }
-        }
-      }
+      buffer.write(context2.name.toString());
+    }
+    buffer.writeln();
+    if (context2.hasPublicInterfaces == true) {
       buffer.writeln();
-      if (context2.hasPublicImplementors == true) {
+      buffer.write('''
+**Implemented types**
+''');
+      var context7 = context2.publicInterfaces;
+      for (var context8 in context7) {
         buffer.writeln();
         buffer.write('''
-**Mixin Applications**
-''');
-        var context9 = context2.publicImplementorsSorted;
-        if (context9 != null) {
-          for (var context10 in context9) {
-            buffer.writeln();
-            buffer.write('''
 - ''');
-            buffer.write(context10.linkedName.toString());
-          }
-        }
+        buffer.write(context8.linkedName.toString());
       }
+    }
+    buffer.writeln();
+    if (context2.hasPublicImplementors == true) {
       buffer.writeln();
-      if (context2.hasAnnotations == true) {
+      buffer.write('''
+**Mixin Applications**
+''');
+      var context9 = context2.publicImplementorsSorted;
+      for (var context10 in context9) {
         buffer.writeln();
         buffer.write('''
-**Annotations**
-''');
-        var context11 = context2.annotations;
-        if (context11 != null) {
-          for (var context12 in context11) {
-            buffer.writeln();
-            buffer.write('''
 - ''');
-            buffer.write(context12.linkedNameWithParameters.toString());
-          }
-        }
+        buffer.write(context10.linkedName.toString());
       }
     }
     buffer.writeln();
-    if (context2.hasPublicInstanceFields == true) {
+    if (context2.hasAnnotations == true) {
       buffer.writeln();
       buffer.write('''
-## Properties
+**Annotations**
 ''');
-      var context13 = context2.publicInstanceFieldsSorted;
-      if (context13 != null) {
-        for (var context14 in context13) {
-          buffer.writeln();
-          buffer.write(
-              _renderMixin_partial_property_5(context14, context2, context0));
-          buffer.writeln();
-        }
+      var context11 = context2.annotations;
+      for (var context12 in context11) {
+        buffer.writeln();
+        buffer.write('''
+- ''');
+        buffer.write(context12.linkedNameWithParameters.toString());
       }
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceFields == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceMethods == true) {
+    buffer.write('''
+## Properties
+''');
+    var context13 = context2.publicInstanceFieldsSorted;
+    for (var context14 in context13) {
       buffer.writeln();
-      buffer.write('''
+      buffer.write(
+          _renderMixin_partial_property_5(context14, context2, context0));
+      buffer.writeln();
+    }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceMethods == true) {
+    buffer.writeln();
+    buffer.write('''
 ## Methods
 ''');
-      var context15 = context2.publicInstanceMethodsSorted;
-      if (context15 != null) {
-        for (var context16 in context15) {
-          buffer.writeln();
-          buffer.write(
-              _renderMixin_partial_callable_6(context16, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context15 = context2.publicInstanceMethodsSorted;
+    for (var context16 in context15) {
+      buffer.writeln();
+      buffer.write(
+          _renderMixin_partial_callable_6(context16, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicInstanceOperators == true) {
     buffer.writeln();
-    if (context2.hasPublicInstanceOperators == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Operators
 ''');
-      var context17 = context2.publicInstanceOperatorsSorted;
-      if (context17 != null) {
-        for (var context18 in context17) {
-          buffer.writeln();
-          buffer.write(
-              _renderMixin_partial_callable_6(context18, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context17 = context2.publicInstanceOperatorsSorted;
+    for (var context18 in context17) {
+      buffer.writeln();
+      buffer.write(
+          _renderMixin_partial_callable_6(context18, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicVariableStaticFields == true) {
     buffer.writeln();
-    if (context2.hasPublicVariableStaticFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Static Properties
 ''');
-      var context19 = context2.publicVariableStaticFieldsSorted;
-      if (context19 != null) {
-        for (var context20 in context19) {
-          buffer.writeln();
-          buffer.write(
-              _renderMixin_partial_property_5(context20, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context19 = context2.publicVariableStaticFieldsSorted;
+    for (var context20 in context19) {
+      buffer.writeln();
+      buffer.write(
+          _renderMixin_partial_property_5(context20, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicStaticMethods == true) {
     buffer.writeln();
-    if (context2.hasPublicStaticMethods == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Static Methods
 ''');
-      var context21 = context2.publicStaticMethodsSorted;
-      if (context21 != null) {
-        for (var context22 in context21) {
-          buffer.writeln();
-          buffer.write(
-              _renderMixin_partial_callable_6(context22, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context21 = context2.publicStaticMethodsSorted;
+    for (var context22 in context21) {
+      buffer.writeln();
+      buffer.write(
+          _renderMixin_partial_callable_6(context22, context2, context0));
+      buffer.writeln();
     }
+  }
+  buffer.writeln();
+  if (context2.hasPublicConstantFields == true) {
     buffer.writeln();
-    if (context2.hasPublicConstantFields == true) {
-      buffer.writeln();
-      buffer.write('''
+    buffer.write('''
 ## Constants
 ''');
-      var context23 = context2.publicConstantFieldsSorted;
-      if (context23 != null) {
-        for (var context24 in context23) {
-          buffer.writeln();
-          buffer.write(
-              _renderMixin_partial_constant_7(context24, context2, context0));
-          buffer.writeln();
-        }
-      }
+    var context23 = context2.publicConstantFieldsSorted;
+    for (var context24 in context23) {
+      buffer.writeln();
+      buffer.write(
+          _renderMixin_partial_constant_7(context24, context2, context0));
+      buffer.writeln();
     }
   }
   buffer.write('\n\n');
@@ -3577,11 +3306,9 @@ String _renderMixin_partial_categorization_2(
     buffer.write('''
 Categories:''');
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3594,11 +3321,9 @@ String _renderMixin_partial_feature_set_3(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -3611,7 +3336,7 @@ String _renderMixin_partial_documentation_4(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -3631,7 +3356,7 @@ String _renderMixin_partial_property_5(
   buffer.write(__renderMixin_partial_property_5_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -3651,11 +3376,9 @@ String __renderMixin_partial_property_5_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3683,14 +3406,14 @@ String _renderMixin_partial_callable_6(
   buffer.write(context2.linkedName.toString());
   buffer.write(context2.linkedGenericParameters.toString());
   buffer.write('''(''');
-  buffer.write(context2.linkedParamsNoMetadata.toString());
+  buffer.write(context2.linkedParamsNoMetadata?.toString());
   buffer.write(''') ''');
   buffer.write(context2.modelType.returnType.linkedName.toString());
   buffer.writeln();
   buffer.write(__renderMixin_partial_callable_6_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -3710,11 +3433,9 @@ String __renderMixin_partial_callable_6_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3746,7 +3467,7 @@ String _renderMixin_partial_constant_7(
   buffer.write(__renderMixin_partial_constant_7_partial_categorization_0(
       context2, context1, context0));
   buffer.write('\n\n');
-  buffer.write(context2.oneLineDoc.toString());
+  buffer.write(context2.oneLineDoc?.toString());
   buffer.write(' ');
   buffer.write(context2.extendedDocLink.toString());
   buffer.write('  ');
@@ -3766,11 +3487,9 @@ String __renderMixin_partial_constant_7_partial_categorization_0(
     buffer.write('''
 Categories:''');
     var context3 = context2.displayedCategories;
-    if (context3 != null) {
-      for (var context4 in context3) {
-        buffer.writeln();
-        buffer.write(context4.categoryLabel.toString());
-      }
+    for (var context4 in context3) {
+      buffer.writeln();
+      buffer.write(context4!.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -3807,47 +3526,43 @@ String renderProperty(_i1.PropertyTemplateData context0) {
   buffer.write(_renderProperty_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.writeEscaped(context1.name.toString());
+  buffer.writeEscaped(context1.name.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderProperty_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderProperty_partial_feature_set_2(context1, context0));
+  buffer.writeln();
+  var context2 = context0.self;
+  if (context2.hasNoGetterSetter == true) {
+    buffer.writeln();
+    buffer.write(context2.modelType.linkedName.toString());
     buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderProperty_partial_source_link_1(context1, context0));
+    buffer.write(_renderProperty_partial_name_summary_3(context2, context0));
+    buffer.write('  ');
     buffer.writeln();
-    buffer.write(_renderProperty_partial_feature_set_2(context1, context0));
+    buffer.write(_renderProperty_partial_features_4(context2, context0));
+    buffer.write('\n\n');
+    buffer.write(_renderProperty_partial_documentation_5(context2, context0));
+    buffer.write('\n\n');
+    buffer.write(_renderProperty_partial_source_code_6(context2, context0));
   }
   buffer.writeln();
-  var context2 = context0.self;
-  if (context2 != null) {
-    if (context2.hasNoGetterSetter == true) {
-      buffer.writeln();
-      buffer.write(context2.modelType.linkedName.toString());
-      buffer.write(' ');
-      buffer.write(_renderProperty_partial_name_summary_3(context2, context0));
-      buffer.write('  ');
+  if (context2.hasGetterOrSetter == true) {
+    if (context2.hasGetter == true) {
       buffer.writeln();
-      buffer.write(_renderProperty_partial_features_4(context2, context0));
-      buffer.write('\n\n');
-      buffer.write(_renderProperty_partial_documentation_5(context2, context0));
-      buffer.write('\n\n');
-      buffer.write(_renderProperty_partial_source_code_6(context2, context0));
+      buffer
+          .write(_renderProperty_partial_accessor_getter_7(context2, context0));
     }
     buffer.writeln();
-    if (context2.hasGetterOrSetter == true) {
-      if (context2.hasGetter == true) {
-        buffer.writeln();
-        buffer.write(
-            _renderProperty_partial_accessor_getter_7(context2, context0));
-      }
+    if (context2.hasSetter == true) {
       buffer.writeln();
-      if (context2.hasSetter == true) {
-        buffer.writeln();
-        buffer.write(
-            _renderProperty_partial_accessor_setter_8(context2, context0));
-      }
+      buffer
+          .write(_renderProperty_partial_accessor_setter_8(context2, context0));
     }
   }
   buffer.write('\n\n');
@@ -3885,11 +3600,9 @@ String _renderProperty_partial_feature_set_2(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -3933,7 +3646,7 @@ String _renderProperty_partial_documentation_5(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -4031,7 +3744,7 @@ String __renderProperty_partial_accessor_getter_7_partial_documentation_2(
   final buffer = StringBuffer();
   if (context2.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context2.documentationAsHtml.toString());
+    buffer.write(context2.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -4070,7 +3783,7 @@ String _renderProperty_partial_accessor_setter_8(
         __renderProperty_partial_accessor_setter_8_partial_name_summary_0(
             context2, context1, context0));
     buffer.write('''(''');
-    buffer.write(context2.linkedParamsNoMetadata.toString());
+    buffer.write(context2.linkedParamsNoMetadata?.toString());
     buffer.write(''')  ''');
     buffer.writeln();
     buffer.write(__renderProperty_partial_accessor_setter_8_partial_features_1(
@@ -4131,7 +3844,7 @@ String __renderProperty_partial_accessor_setter_8_partial_documentation_2(
   final buffer = StringBuffer();
   if (context2.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context2.documentationAsHtml.toString());
+    buffer.write(context2.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -4190,52 +3903,50 @@ String renderTopLevelProperty(_i1.TopLevelPropertyTemplateData context0) {
   buffer.write(_renderTopLevelProperty_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.name.toString());
+  buffer.write(context1.name.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer
+      .write(_renderTopLevelProperty_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(
+      _renderTopLevelProperty_partial_categorization_2(context1, context0));
+  buffer.writeln();
+  buffer
+      .write(_renderTopLevelProperty_partial_feature_set_3(context1, context0));
+  buffer.writeln();
+  if (context1.hasNoGetterSetter == true) {
+    buffer.writeln();
+    buffer.write(context1.modelType.linkedName.toString());
     buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
     buffer.write(
-        _renderTopLevelProperty_partial_source_link_1(context1, context0));
+        _renderTopLevelProperty_partial_name_summary_4(context1, context0));
+    buffer.write('  ');
     buffer.writeln();
+    buffer
+        .write(_renderTopLevelProperty_partial_features_5(context1, context0));
+    buffer.write('\n\n');
     buffer.write(
-        _renderTopLevelProperty_partial_categorization_2(context1, context0));
-    buffer.writeln();
+        _renderTopLevelProperty_partial_documentation_6(context1, context0));
+    buffer.write('\n\n');
     buffer.write(
-        _renderTopLevelProperty_partial_feature_set_3(context1, context0));
-    buffer.writeln();
-    if (context1.hasNoGetterSetter == true) {
-      buffer.writeln();
-      buffer.write(context1.modelType.linkedName.toString());
-      buffer.write(' ');
-      buffer.write(
-          _renderTopLevelProperty_partial_name_summary_4(context1, context0));
-      buffer.write('  ');
-      buffer.writeln();
-      buffer.write(
-          _renderTopLevelProperty_partial_features_5(context1, context0));
-      buffer.write('\n\n');
-      buffer.write(
-          _renderTopLevelProperty_partial_documentation_6(context1, context0));
-      buffer.write('\n\n');
-      buffer.write(
-          _renderTopLevelProperty_partial_source_code_7(context1, context0));
-    }
+        _renderTopLevelProperty_partial_source_code_7(context1, context0));
+  }
+  buffer.writeln();
+  if (context1.hasExplicitGetter == true) {
     buffer.writeln();
-    if (context1.hasExplicitGetter == true) {
-      buffer.writeln();
-      buffer.write(_renderTopLevelProperty_partial_accessor_getter_8(
-          context1, context0));
-    }
+    buffer.write(
+        _renderTopLevelProperty_partial_accessor_getter_8(context1, context0));
+  }
+  buffer.writeln();
+  if (context1.hasExplicitSetter == true) {
     buffer.writeln();
-    if (context1.hasExplicitSetter == true) {
-      buffer.writeln();
-      buffer.write(_renderTopLevelProperty_partial_accessor_setter_9(
-          context1, context0));
-    }
+    buffer.write(
+        _renderTopLevelProperty_partial_accessor_setter_9(context1, context0));
   }
   buffer.write('\n\n');
   buffer.write(_renderTopLevelProperty_partial_footer_10(context0));
@@ -4276,11 +3987,9 @@ String _renderTopLevelProperty_partial_categorization_2(
     buffer.write('''
 Categories:''');
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -4293,11 +4002,9 @@ String _renderTopLevelProperty_partial_feature_set_3(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -4341,7 +4048,7 @@ String _renderTopLevelProperty_partial_documentation_6(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -4442,7 +4149,7 @@ String
   final buffer = StringBuffer();
   if (context2.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context2.documentationAsHtml.toString());
+    buffer.write(context2.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -4481,7 +4188,7 @@ String _renderTopLevelProperty_partial_accessor_setter_9(
         __renderTopLevelProperty_partial_accessor_setter_9_partial_name_summary_0(
             context2, context1, context0));
     buffer.write('''(''');
-    buffer.write(context2.linkedParamsNoMetadata.toString());
+    buffer.write(context2.linkedParamsNoMetadata?.toString());
     buffer.write(''')  ''');
     buffer.writeln();
     buffer.write(
@@ -4545,7 +4252,7 @@ String
   final buffer = StringBuffer();
   if (context2.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context2.documentationAsHtml.toString());
+    buffer.write(context2.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -4591,31 +4298,26 @@ String renderTypedef(_i1.TypedefTemplateData context0) {
   buffer.write(_renderTypedef_partial_head_0(context0));
   buffer.writeln();
   var context1 = context0.self;
-  if (context1 != null) {
-    buffer.writeln();
-    buffer.write('''
+  buffer.writeln();
+  buffer.write('''
 # ''');
-    buffer.write(context1.nameWithGenerics.toString());
-    buffer.write(' ');
-    buffer.writeEscaped(context1.kind.toString());
-    buffer.write('\n\n');
-    buffer.write(_renderTypedef_partial_source_link_1(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderTypedef_partial_categorization_2(context1, context0));
-    buffer.writeln();
-    buffer.write(_renderTypedef_partial_feature_set_3(context1, context0));
-  }
+  buffer.write(context1.nameWithGenerics.toString());
+  buffer.write(' ');
+  buffer.writeEscaped(context1.kind.toString());
+  buffer.write('\n\n');
+  buffer.write(_renderTypedef_partial_source_link_1(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderTypedef_partial_categorization_2(context1, context0));
+  buffer.writeln();
+  buffer.write(_renderTypedef_partial_feature_set_3(context1, context0));
   buffer.writeln();
   var context2 = context0.typeDef;
-  if (context2 != null) {
-    buffer.writeln();
-    buffer
-        .write(_renderTypedef_partial_typedef_multiline_4(context2, context0));
-    buffer.write('\n\n');
-    buffer.write(_renderTypedef_partial_documentation_5(context2, context0));
-    buffer.write('\n\n');
-    buffer.write(_renderTypedef_partial_source_code_6(context2, context0));
-  }
+  buffer.writeln();
+  buffer.write(_renderTypedef_partial_typedef_multiline_4(context2, context0));
+  buffer.write('\n\n');
+  buffer.write(_renderTypedef_partial_documentation_5(context2, context0));
+  buffer.write('\n\n');
+  buffer.write(_renderTypedef_partial_source_code_6(context2, context0));
   buffer.write('\n\n');
   buffer.write(_renderTypedef_partial_footer_7(context0));
   buffer.writeln();
@@ -4654,11 +4356,9 @@ String _renderTypedef_partial_categorization_2(
     buffer.write('''
 Categories:''');
     var context2 = context1.displayedCategories;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write(context3.categoryLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write(context3.categoryLabel.toString());
     }
   }
   buffer.writeln();
@@ -4671,11 +4371,9 @@ String _renderTypedef_partial_feature_set_3(
   final buffer = StringBuffer();
   if (context1.hasFeatureSet == true) {
     var context2 = context1.displayedLanguageFeatures;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.write('\n    ');
-        buffer.write(context3.featureLabel.toString());
-      }
+    for (var context3 in context2) {
+      buffer.write('\n    ');
+      buffer.write(context3.featureLabel.toString());
     }
   }
   buffer.writeln();
@@ -4688,26 +4386,22 @@ String _renderTypedef_partial_typedef_multiline_4(
   final buffer = StringBuffer();
   if (context1.isCallable == true) {
     var context2 = context1.asCallable;
-    if (context2 != null) {
-      if (context2.hasAnnotations == true) {
-        var context3 = context2.annotations;
-        if (context3 != null) {
-          for (var context4 in context3) {
-            buffer.writeln();
-            buffer.write('''
+    if (context2.hasAnnotations == true) {
+      var context3 = context2.annotations;
+      for (var context4 in context3) {
+        buffer.writeln();
+        buffer.write('''
     - ''');
-            buffer.write(context4.linkedNameWithParameters.toString());
-          }
-        }
+        buffer.write(context4.linkedNameWithParameters.toString());
       }
-      buffer.write('\n\n    ');
-      buffer.write(context2.modelType.returnType.linkedName.toString());
-      buffer.write(' ');
-      buffer.writeEscaped(context2.name.toString());
-      buffer.write(context2.linkedGenericParameters.toString());
-      buffer.write(''' = ''');
-      buffer.write(context2.modelType.linkedName.toString());
     }
+    buffer.write('\n\n    ');
+    buffer.write(context2.modelType.returnType.linkedName.toString());
+    buffer.write(' ');
+    buffer.writeEscaped(context2.name.toString());
+    buffer.write(context2.linkedGenericParameters.toString());
+    buffer.write(''' = ''');
+    buffer.write(context2.modelType.linkedName.toString());
   }
   if (context1.isCallable != true) {
     buffer.write('\n  ');
@@ -4725,13 +4419,11 @@ String __renderTypedef_partial_typedef_multiline_4_partial_type_multiline_0(
   final buffer = StringBuffer();
   if (context1.hasAnnotations == true) {
     var context2 = context1.annotations;
-    if (context2 != null) {
-      for (var context3 in context2) {
-        buffer.writeln();
-        buffer.write('''
+    for (var context3 in context2) {
+      buffer.writeln();
+      buffer.write('''
 - ''');
-        buffer.write(context3.linkedNameWithParameters.toString());
-      }
+      buffer.write(context3.linkedNameWithParameters.toString());
     }
   }
   buffer.write('\n\n');
@@ -4770,7 +4462,7 @@ String _renderTypedef_partial_documentation_5(
   final buffer = StringBuffer();
   if (context1.hasDocumentation == true) {
     buffer.writeln();
-    buffer.write(context1.documentationAsHtml.toString());
+    buffer.write(context1.documentationAsHtml?.toString());
   }
   buffer.writeln();
 
@@ -4809,7 +4501,7 @@ String _renderTypedef_partial_footer_7(_i1.TypedefTemplateData context0) {
 }
 
 extension on StringBuffer {
-  void writeEscaped(String value) {
-    write(_i19.htmlEscape.convert(value));
+  void writeEscaped(String? value) {
+    write(_i19.htmlEscape.convert(value ?? ''));
   }
 }
diff --git a/test/mustachio/aot_compiler_render_test.dart b/test/mustachio/aot_compiler_render_test.dart
index 37469af23b..470de5e807 100644
--- a/test/mustachio/aot_compiler_render_test.dart
+++ b/test/mustachio/aot_compiler_render_test.dart
@@ -23,43 +23,43 @@ void main() {
   final sdk = p.dirname(p.dirname(Platform.resolvedExecutable));
   final fooCode = '''
 class FooBase<T extends Object> {
-  T baz;
+  T? baz;
 }
 
 class Foo extends FooBase<Baz> {
-String s1;
-bool b1;
-List<int> l1;
-@override
-Baz baz;
-Property1 p1;
+  String? s1 = '';
+  bool b1 = false;
+  List<int> l1 = [];
+  @override
+  Baz? baz;
+  Property1? p1;
 }
 
 class Bar {
-  Foo foo;
-  String s2;
-  Baz baz;
-  bool l1;
+  Foo? foo;
+  String? s2;
+  Baz? baz;
+  bool? l1;
 }
 
 class Baz {
-  Bar bar;
+  Bar? bar;
 }
 
 class Property1 {
-  Property2 p2;
+  Property2? p2;
 }
 
 class Property2 with Mixin1 {
-  String s;
+  String? s;
 }
 
 mixin Mixin1 {
-  Property3 p3;
+  Property3? p3;
 }
 
 class Property3 {
-  String s;
+  String? s;
 }
 ''';
   InMemoryAssetWriter writer;
@@ -100,7 +100,7 @@ $mainCode
         'foo',
         Uri.directory(tempDir.path),
         packageUriRoot: Uri.directory(p.join(tempDir.path, 'lib')),
-        languageVersion: LanguageVersion(2, 9),
+        languageVersion: LanguageVersion(2, 12),
       )
     ]);
     var dartToolDir = Directory(p.join(tempDir.path, '.dart_tool'))
@@ -368,7 +368,7 @@ void main() {
               'Text {{#bar}}{{bar.foo.baz.bar.foo.s1}}{{/bar}}',
         },
         '_i1.Baz()..bar = (_i1.Bar()..foo = (_i1.Foo()..s1 = "hello"));'
-        'baz.bar.foo.baz = baz');
+        'baz.bar!.foo!.baz = baz');
     expect(output, equals('Text hello'));
   });
 
@@ -461,7 +461,7 @@ line 1, column 9 of package:foo/templates/html/foo.html: Failed to resolve '[s2]
             }, '_i1.Bar()..foo = _i1.Foo()'),
         throwsA(const TypeMatcher<MustachioResolutionError>()
             .having((e) => e.message, 'message', contains('''
-line 1, column 8 of package:foo/templates/html/bar.html: Failed to resolve 'x' on Bar while resolving [x] as a property chain on any types in the context chain: context0.foo, after first resolving 'foo' to a property on Foo
+line 1, column 8 of package:foo/templates/html/bar.html: Failed to resolve 'x' on Bar while resolving [x] as a property chain on any types in the context chain: context0.foo, after first resolving 'foo' to a property on Foo?
   ╷
 1 │ Text {{foo.x}}
   │        ^^^^^
diff --git a/test/mustachio/foo.aot_renderers_for_html.dart b/test/mustachio/foo.aot_renderers_for_html.dart
index 78e25dc754..318b2fdd62 100644
--- a/test/mustachio/foo.aot_renderers_for_html.dart
+++ b/test/mustachio/foo.aot_renderers_for_html.dart
@@ -7,7 +7,6 @@
 // the variable is not used; generally when the section is checking if a
 // non-bool, non-Iterable field is non-null.
 // ignore_for_file: unused_local_variable
-// @dart=2.9
 // ignore_for_file: non_constant_identifier_names, unnecessary_string_escapes
 
 import 'dart:convert' as _i2;
@@ -23,7 +22,7 @@ String renderFoo(_i1.Foo context0) {
   buffer.write('''
 
     s1: ''');
-  buffer.writeEscaped(context0.s1.toString());
+  buffer.writeEscaped(context0.s1?.toString());
   buffer.writeln();
   buffer.write('''
     b1? ''');
@@ -37,13 +36,11 @@ String renderFoo(_i1.Foo context0) {
   buffer.write('''
     l1:''');
   var context1 = context0.l1;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.write('''item: ''');
-      buffer.writeEscaped(context2.toString());
-    }
+  for (var context2 in context1) {
+    buffer.write('''item: ''');
+    buffer.writeEscaped(context2.toString());
   }
-  if (context0.l1?.isEmpty ?? true) {
+  if (context0.l1.isEmpty) {
     buffer.write('''no items''');
   }
   buffer.writeln();
@@ -54,7 +51,7 @@ String renderFoo(_i1.Foo context0) {
     buffer.writeln();
     buffer.write('''
     Baz has a ''');
-    buffer.writeEscaped(context3.bar.s2.toString());
+    buffer.writeEscaped(context3.bar!.s2?.toString());
   }
   if (context0.baz == null) {
     buffer.write('''baz is null''');
@@ -91,7 +88,7 @@ String renderBaz(_i1.Baz context0) {
 }
 
 extension on StringBuffer {
-  void writeEscaped(String value) {
-    write(_i2.htmlEscape.convert(value));
+  void writeEscaped(String? value) {
+    write(_i2.htmlEscape.convert(value ?? ''));
   }
 }
diff --git a/test/mustachio/foo.aot_renderers_for_md.dart b/test/mustachio/foo.aot_renderers_for_md.dart
index ba9ffb1d26..57cfdde145 100644
--- a/test/mustachio/foo.aot_renderers_for_md.dart
+++ b/test/mustachio/foo.aot_renderers_for_md.dart
@@ -7,7 +7,6 @@
 // the variable is not used; generally when the section is checking if a
 // non-bool, non-Iterable field is non-null.
 // ignore_for_file: unused_local_variable
-// @dart=2.9
 // ignore_for_file: non_constant_identifier_names, unnecessary_string_escapes
 
 import 'dart:convert' as _i2;
@@ -21,7 +20,7 @@ String renderFoo(_i1.Foo context0) {
   buffer.write('''
 
 s1: ''');
-  buffer.writeEscaped(context0.s1.toString());
+  buffer.writeEscaped(context0.s1?.toString());
   buffer.writeln();
   buffer.write('''
 b1? ''');
@@ -35,13 +34,11 @@ b1? ''');
   buffer.write('''
 l1:''');
   var context1 = context0.l1;
-  if (context1 != null) {
-    for (var context2 in context1) {
-      buffer.write('''item: ''');
-      buffer.writeEscaped(context2.toString());
-    }
+  for (var context2 in context1) {
+    buffer.write('''item: ''');
+    buffer.writeEscaped(context2.toString());
   }
-  if (context0.l1?.isEmpty ?? true) {
+  if (context0.l1.isEmpty) {
     buffer.write('''no items''');
   }
   buffer.writeln();
@@ -52,7 +49,7 @@ baz:''');
     buffer.writeln();
     buffer.write('''
 Baz has a ''');
-    buffer.writeEscaped(context3.bar.s2.toString());
+    buffer.writeEscaped(context3.bar!.s2?.toString());
   }
   if (context0.baz == null) {
     buffer.write('''baz is null''');
@@ -82,7 +79,7 @@ String renderBaz(_i1.Baz context0) {
 }
 
 extension on StringBuffer {
-  void writeEscaped(String value) {
-    write(_i2.htmlEscape.convert(value));
+  void writeEscaped(String? value) {
+    write(_i2.htmlEscape.convert(value ?? ''));
   }
 }
diff --git a/test/mustachio/foo.dart b/test/mustachio/foo.dart
index 8600431bb4..b07d3cdd6a 100644
--- a/test/mustachio/foo.dart
+++ b/test/mustachio/foo.dart
@@ -11,7 +11,7 @@ class FooBase<T extends Object> {
 }
 
 class Foo extends FooBase<Baz> {
-  String s1 = '';
+  String? s1 = '';
   bool b1 = false;
   List<int> l1 = [];
   @override
diff --git a/test/mustachio/foo.runtime_renderers.dart b/test/mustachio/foo.runtime_renderers.dart
index 13b392d97d..bb44c210a2 100644
--- a/test/mustachio/foo.runtime_renderers.dart
+++ b/test/mustachio/foo.runtime_renderers.dart
@@ -265,7 +265,7 @@ class Renderer_Foo extends RendererBase<Foo?> {
                   renderVariable: (CT_ c, Property<CT_> self,
                           List<String> remainingNames) =>
                       self.renderSimpleVariable(c, remainingNames, 'String'),
-                  isNullValue: (CT_ c) => false,
+                  isNullValue: (CT_ c) => c.s1 == null,
                   renderValue: (CT_ c, RendererBase<CT_> r,
                       List<MustachioNode> ast, StringSink sink) {
                     renderSimple(c.s1, ast, r.template, sink,
diff --git a/tool/mustachio/codegen_aot_compiler.dart b/tool/mustachio/codegen_aot_compiler.dart
index 7019b3c1d8..4c411b5108 100644
--- a/tool/mustachio/codegen_aot_compiler.dart
+++ b/tool/mustachio/codegen_aot_compiler.dart
@@ -50,12 +50,12 @@ Future<String> compileTemplatesToRenderers(
         ..returns = refer('void')
         ..name = 'writeEscaped'
         ..requiredParameters.add(Parameter((b) => b
-          ..type = refer('String')
+          ..type = refer('String?')
           ..name = 'value'))
         ..body = refer('write').call([
           refer('htmlEscape', 'dart:convert')
               .property('convert')
-              .call([refer('value')])
+              .call([refer("value ?? ''")])
         ]).statement))));
   });
   return DartFormatter().format('''
@@ -68,7 +68,6 @@ Future<String> compileTemplatesToRenderers(
 // the variable is not used; generally when the section is checking if a
 // non-bool, non-Iterable field is non-null.
 // ignore_for_file: unused_local_variable
-// @dart=2.9
 // ignore_for_file: non_constant_identifier_names, unnecessary_string_escapes
 
 ${library.accept(DartEmitter.scoped(orderDirectives: true))}
@@ -154,8 +153,7 @@ class _AotCompiler {
 
   Future<List<Method>> _compileToRenderer() async {
     if (_contextStack.isEmpty) {
-      var contextName = 'context0';
-      var contextVariable = _VariableLookup(_contextType, contextName);
+      var contextVariable = _VariableLookup(_contextType, 'context0');
       _contextStack.push(contextVariable);
       _contextNameCounter++;
     }
@@ -361,16 +359,24 @@ class _BlockCompiler {
   Future<void> _compileRepeatedSection(
       _VariableLookup variableLookup, List<MustachioNode> block,
       {bool invert = false}) async {
+    var variableIsPotentiallyNullable =
+        typeSystem.isPotentiallyNullable(variableLookup.type);
     var variableAccess = variableLookup.name;
     if (invert) {
-      writeln('if ($variableAccess?.isEmpty ?? true) {');
+      if (variableIsPotentiallyNullable) {
+        writeln('if ($variableAccess?.isEmpty ?? true) {');
+      } else {
+        writeln('if ($variableAccess.isEmpty) {');
+      }
       await _compile(block);
       writeln('}');
     } else {
       var variableAccessResult = getNewContextName();
       writeln('var $variableAccessResult = $variableAccess;');
       var newContextName = getNewContextName();
-      writeln('if ($variableAccessResult != null) {');
+      if (variableIsPotentiallyNullable) {
+        writeln('if ($variableAccessResult != null) {');
+      }
       writeln('  for (var $newContextName in $variableAccessResult) {');
       // If [loopType] is something like `C<int>` where
       // `class C<T> implements Queue<Future<T>>`, we need the [ClassElement]
@@ -385,7 +391,9 @@ class _BlockCompiler {
       await _compile(block);
       _contextStack.pop();
       writeln('  }');
-      writeln('}');
+      if (variableIsPotentiallyNullable) {
+        writeln('}');
+      }
     }
   }
 
@@ -394,6 +402,8 @@ class _BlockCompiler {
       _VariableLookup variableLookup, List<MustachioNode> block,
       {bool invert = false}) async {
     var variableAccess = variableLookup.name;
+    var variableIsPotentiallyNullable =
+        typeSystem.isPotentiallyNullable(variableLookup.type);
     if (invert) {
       writeln('if ($variableAccess == null) {');
       await _compile(block);
@@ -401,12 +411,18 @@ class _BlockCompiler {
     } else {
       var innerContextName = getNewContextName();
       writeln('var $innerContextName = $variableAccess;');
-      writeln('if ($innerContextName != null) {');
-      var innerContext = _VariableLookup(variableLookup.type, innerContextName);
+      if (variableIsPotentiallyNullable) {
+        writeln('if ($innerContextName != null) {');
+      }
+      var innerContext = _VariableLookup(
+          typeSystem.promoteToNonNull(variableLookup.type) as InterfaceType,
+          innerContextName);
       _contextStack.push(innerContext);
       await _compile(block);
       _contextStack.pop();
-      writeln('}');
+      if (variableIsPotentiallyNullable) {
+        writeln('}');
+      }
     }
   }
 
@@ -429,12 +445,18 @@ class _BlockCompiler {
         continue;
       }
 
-      var type = getter.returnType;
-      var contextChain = '${context.name}.$primaryName';
+      var type = getter.returnType as InterfaceType;
+      var contextChain = typeSystem.isPotentiallyNullable(context.type)
+          // This is imperfect; the idea is that in our templates, we may have
+          // `{{foo.bar.baz}}` and `foo.bar` may be nullably typed. Mustache
+          // (and Mustachio) does not have a null-aware property access
+          // operator, nor a null-check operator. This code translates
+          // `foo.bar.baz` to `foo.bar!.baz` for nullable `foo.bar`.
+          ? '${context.name}!.$primaryName'
+          : '${context.name}.$primaryName';
       var remainingNames = [...key.skip(1)];
       for (var secondaryKey in remainingNames) {
-        getter = (type as InterfaceType)
-            .lookUpGetter2(secondaryKey, type.element.library);
+        getter = type.lookUpGetter2(secondaryKey, type.element.library);
         if (getter == null) {
           throw MustachioResolutionError(node.keySpan.message(
               "Failed to resolve '$secondaryKey' on ${context.type} while "
@@ -442,10 +464,12 @@ class _BlockCompiler {
               'the context chain: $contextChain, after first resolving '
               "'$primaryName' to a property on $type"));
         }
-        type = getter.returnType;
-        contextChain = '$contextChain.$secondaryKey';
+        contextChain = typeSystem.isPotentiallyNullable(type)
+            ? '$contextChain!.$secondaryKey'
+            : '$contextChain.$secondaryKey';
+        type = getter.returnType as InterfaceType;
       }
-      return _VariableLookup(type as InterfaceType, contextChain);
+      return _VariableLookup(type, contextChain);
     }
 
     var contextTypes = [
@@ -491,11 +515,12 @@ class _BlockCompiler {
   /// The result is HTML-escaped if [escape] is true.
   void _writeGetter(_VariableLookup variableLookup, {bool escape = true}) {
     var variableAccess = variableLookup.name;
-    if (escape) {
-      writeln('buffer.writeEscaped($variableAccess.toString());');
-    } else {
-      writeln('buffer.write($variableAccess.toString());');
-    }
+    var toString = typeSystem.isPotentiallyNullable(variableLookup.type)
+        ? '$variableAccess?.toString()'
+        : '$variableAccess.toString()';
+    writeln(escape
+        ? 'buffer.writeEscaped($toString);'
+        : 'buffer.write($toString);');
   }
 }