1. @override
void startSendingData(int currentTime, int waitingAckId)

Source

@override
void startSendingData(int currentTime, int waitingAckId) {
  _pendingSending = false;

  if (waitingAckId != -1) {
    _waitingAckCount++;
    _lastWaitingAckId = waitingAckId;
  }

  List updates = new List();
  for (RespSubscribeController controller in changed) {
    updates.addAll(controller.process(waitingAckId));
  }
  responder.updateResponse(this, updates);
  changed.clear();
}