anchor.diff:      }
     }
   
  -  Future<void> _dispatch(List<List> calls) async {
  +  void _dispatch(List<List> calls) async {
       final n = calls.length;
       final results = new List<Future>(n);
       for (var i = 0; i < n; i++) {
  
positive.code:   bool _send(String id, Completer<List<List>> responder) {
      if (_calls.containsKey(id)) {
        final calls = _calls[id];
        if (calls.length == 0) {
          return false;
        }
        _calls[id] = [];
  
negative.code:             responder.complete([]);
            }
          });
          await responder.future.then((value) {
            timeoutTimer.cancel();
          });
        }
  