Merge pull request #48 from magento-commerce/fix_NullableType

fix NullableType

Author: duhon

src/Analyzer/ClassMethodAnalyzer.php

@@ -459,7 +459,11 @@ private function getDocReturnDeclaration(ClassMethod $method)
             ($parsedComment = $method->getAttribute('docCommentParsed'))
             && isset($parsedComment['return'])
         ) {
-            $result = implode('|', $parsedComment['return']);
+            if ($parsedComment['return'][0] instanceof NullableType) {
+                $result =  '?' . $parsedComment['return'][0]->type;
+            } else {
+                $result = implode('|', $parsedComment['return']);
+            }
 
             return $result;
         } elseif ($this->dependencyGraph !== null) {