anchor.diff:    @override
     Future addStream(Stream stream) => _output.addStream(stream);
   
  -  Future close() =>
  -      _output.close();
  +  Future close() => _output.close();
   
     void header(dynamic entry) {
       _header.add(entry.toString());
     }
  -
   
     void _createListener(DataFunction onData, DataFunction onError, DoneFunction onDone) {
       _output.stream.listen((data) {
  
positive.code: 
    int get requestId => request.requestId;
  
  
    @override
    void add(event) {
      _output.add(event);
  
negative.code: 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
  
  