void startSendingData(int currentTime, int waitingAckId)

Source 

void startSendingData(int currentTime, int waitingAckId) {
  if (!waitToSend) {
    return;
  }
  request = requester._sendRequest(
            {'method': 'list', 'path': node.remotePath}, this);
  waitToSend = false;
}