anchor.diff:  
     @override
     noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
  -}
  -
  -/**
  - * Representation of an interface type during linking.
  - *
  - * TODO(paulberry): add the ability to represent type arguments.
  - */
  -class InterfaceTypeForLink extends DartTypeForLink implements InterfaceType {
  -  @override
  -  final ClassElementForLink element;
  -
  -  InterfaceTypeForLink(this.element);
   }
   
   /**
  
positive.code:   ConstructorElementForLink get unnamedConstructor => null;
  
    @override
    DartTypeForLink buildType(DartTypeForLink getTypeArgument(int i),
            List<int> implicitFunctionTypeIndices) =>
        _type ??= new InterfaceTypeForLink(this);
  
    @override
    void link(LinkedUnitBuilder linkedUnit) {}
  
negative.code:   String get name => _unlinkedClass.name;
  
    @override
    InterfaceType get supertype {
      if (isObject) {
        return null;
      }
  