code: public void sendShortPoll() {
          myExec.execute(new Runnable() {
              @Override
              public void run() {
                  Object[] req = new Object[] { "SP", lastSeenSeq };
                  sendCallArray(req);
              }
          });
      }
docs: send an empty request polling for messages on server side. Unlike long poll,
  this request returns immediately and is not delayed by the server