anchor.diff:      return new _FunctionTypeMirrorImpl(_typedefMirror.referent, _reflectable);
     }
   
  -  @override operator ==(other) {
  +  @override
  +  operator ==(other) {
       return other is _TypedefMirrorImpl &&
           other._typedefMirror == _typedefMirror;
     }
  
positive.code:     for (dm.DeclarationMirror declaration in classMirror.declarations.values) {
        if (declaration is dm.VariableMirror) {
          dm.TypeMirror typeMirror = declaration.type.originalDeclaration;
          if (typeMirror is dm.ClassMirror) yield typeMirror;
        } else if (declaration is dm.MethodMirror) {
          for (dm.ParameterMirror parameter in declaration.parameters) {
            dm.TypeMirror typeMirror = parameter.type.originalDeclaration;
            if (typeMirror is dm.ClassMirror) yield typeMirror;
          }
          dm.TypeMirror typeMirror = declaration.returnType;
          if (typeMirror is dm.ClassMirror) yield typeMirror;
        }
      }
      for (dm.TypeVariableMirror typeVariableMirror
          in classMirror.typeVariables) {
        dm.TypeMirror typeMirror = typeVariableMirror.upperBound;
        if (typeMirror is dm.ClassMirror) {
          yield typeMirror;
        }
      }
  
negative.code:   _SpecialTypeMirrorImpl(dm.TypeMirror typeMirror, ReflectableImpl reflectable)
        : super(typeMirror, reflectable);
  
    @override
    operator ==(other) {
      return other is _SpecialTypeMirrorImpl && other._typeMirror == _typeMirror;
    }
  
  