anchor.diff:    TypeParameter._();
   
     factory TypeParameter([updates(TypeParameterBuilder b)]) = _$TypeParameter;
  -
  -  factory TypeParameter.build(
  -      {String docComment, String name, Classifier bound}) {
  -    return (new TypeParameterBuilder()
  -          ..docComment = docComment
  -          ..name = name
  -          ..bound = bound)
  -        .build();
  -  }
   }
   
   abstract class TypeParameterBuilder
  
positive.code:   GenericType._();
  
    factory GenericType([updates(GenericTypeBuilder b)]) = _$GenericType;
  
    factory GenericType.build(
        {String docComment,
        String name,
        Classifier base,
        MapBuilder<TypeParameter, Classifier> genericTypeValues}) {
      return (new GenericTypeBuilder()
            ..docComment = docComment
            ..name = name
            ..base = base
            ..genericTypeValues =
                genericTypeValues ?? new MapBuilder<TypeParameter, Classifier>())
          .build();
    }
  }
  
  abstract class GenericTypeBuilder
  
negative.code:   ExternalClass._();
  
    factory ExternalClass([updates(ExternalClassBuilder b)]) = _$ExternalClass;
  }
  
  abstract class ExternalClassBuilder
  