anchor.diff:    int _chunkSize;
     bool _inputClosed = false;  // Is the underlying input stream closed?
     bool _closed = false;  // Has the close handler been called?.
  -  var _clientDataHandler;
  -  var _clientCloseHandler;
  +  Timer _scheduledDataCallback;
  +  Timer _scheduledCloseCallback;
  +  Function _clientDataHandler;
  +  Function _clientCloseHandler;
   }
  
positive.code:     // TODO(sgjesse): Find a better way of scheduling callbacks from
      // the event loop.
      void issueDataCallback(Timer timer) {
        if (_clientDataHandler !== null) {
          _clientDataHandler();
          _checkScheduleCallback();
  
negative.code:     }
  
      void issueCloseCallback(Timer timer) {
        _scheduledCloseCallback = null;
        if (!_closed) {
          if (_clientCloseHandler !== null) _clientCloseHandler();
          _closed = true;
  