anchor.diff:    Future close([int code, String reason]) =>
         controller.close().then((_) => twin.controller.close());
   
  -  StreamSubscription<T> listen(void onData(T event),
  +  StreamSubscription<T> listen(void onData(dynamic event),
             {Function onError, void onDone(), bool cancelOnError}) =>
  -      stream.listen(onData,
  +      stream.listen((T data) => onData(data),
             onError: onError, onDone: onDone, cancelOnError: cancelOnError);
   
     noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
   
  -  Stream<T> where(bool test(T t)) => stream.where(test);
  +  Stream<T> where(bool test(dynamic t)) => stream.where((T data) => test(data));
   }
   
   class MockSource extends StringTypedMock implements Source {
  
positive.code:     pumpEventQueue().then((_) {
        responseController.addError(new NoResponseException(request));
      });
      return responseController.stream.firstWhere((response) {
        return response.id == id;
      });
    }
  }
  
  
negative.code:     return socket1;
    }
  
    void add(dynamic text) => controller.add(text as T);
  
    void allowMultipleListeners() {
      stream = stream.asBroadcastStream();
  