Adding a utility for checking java generic class

Author: svorenova

unit/testing-utils/require_type.cpp

@@ -201,3 +201,15 @@ const typet &require_type::require_java_non_generic_type(
     REQUIRE(type.subtype()==expect_subtype.value());
   return type;
 }
+
+/// Verify that a class is a valid java generic class
+/// \param class_type: the class
+/// \return: A reference to the java generic class type.
+java_generics_class_typet &
+require_type::require_java_generic_class(const class_typet &class_type)
+{
+  java_class_typet java_class_type = to_java_class_type(class_type);
+
+  REQUIRE(is_java_generics_class_type(java_class_type));
+  return to_java_generics_class_type(java_class_type);
+}

unit/testing-utils/require_type.h

@@ -62,6 +62,9 @@ java_generic_parametert require_java_generic_parameter(
 const typet &require_java_non_generic_type(
   const typet &type,
   const optionalt<symbol_typet> &expect_subtype);
+
+java_generics_class_typet &
+require_java_generic_class(const class_typet &class_type);
 }
 
 #endif // CPROVER_TESTING_UTILS_REQUIRE_TYPE_H