anchor.diff:      // TODO(sgjesse): Find a better way of scheduling callbacks from
       // the event loop.
       void issueDataCallback(Timer timer) {
  +      _scheduledDataCallback = null;
         if (_clientDataHandler !== null) {
           _clientDataHandler();
           _checkScheduleCallback();
  
positive.code:     // Schedule data callback if enough data in buffer.
      if ((_bufferList.length >=_chunkSize ||
           (_bufferList.length > 0 && _inputClosed)) &&
          _clientDataHandler !== null) {
        new Timer(issueDataCallback, 0, false);
      }
  
      // Schedule close callback if no more data and input is closed.
      if (_bufferList.length == 0 && _inputClosed && !_closed) {
        new Timer(issueCloseCallback, 0, false);
      }
    }
  
  
negative.code:     }
  
      void issueCloseCallback(Timer timer) {
        _scheduledCloseCallback = null;
        if (!_closed) {
          if (_clientCloseHandler !== null) _clientCloseHandler();
          _closed = true;
  