anchor.diff:  typedef void DoneFunction(Response);
   
   class Response implements StreamSink {
  -
     //TODO: move isolate to response object
     //TODO: move control / data / error ports into response object from connection_handler
   
  
positive.code:   @override
    Future addStream(Stream stream) => _output.addStream(stream);
  
    Future close() =>
        _output.close();
  
    void header(dynamic entry) {
      _header.add(entry.toString());
    }
  
  
    void _createListener(DataFunction onData, DataFunction onError, DoneFunction onDone) {
      _output.stream.listen((data) {
  
negative.code: 
    int get requestId => request.requestId;
  
    @override
    void add(event) {
      _output.add(event);
  