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:   ValueClass._();
  
    factory ValueClass([updates(ValueClassBuilder b)]) = _$ValueClass;
  
    factory ValueClass.build(
        {String docComment,
        String name,
        SetBuilder<TypeParameter> genericTypes,
        SetBuilder<Property> properties,
        bool isAbstract,
        SetBuilder<ValuableClass> superTypes}) {
      return (new ValueClassBuilder()
            ..docComment = docComment
            ..name = name
            ..genericTypes = genericTypes ?? new SetBuilder<TypeParameter>()
            ..properties = properties ?? new SetBuilder<Property>()
            ..isAbstract = isAbstract ?? false
            ..superTypes = superTypes ?? new SetBuilder<ValuableClass>())
          .build();
    }
  }
  
  abstract class ValueClassBuilder
  
negative.code:   Package._();
  
    factory Package([updates(PackageBuilder b)]) = _$Package;
  }
  
  abstract class PackageBuilder implements Builder<Package, PackageBuilder> {
  