code: def _thread_worker(self):
          
          while self._running:
              # Retrieve next cmd, or block
              packet = self._queue.get(True)
              if isinstance(packet, dict) and QS_CMD in packet:
                  try:
                      self._callback_listen(packet)
                  except Exception as err:  # pylint: disable=broad-except
                      _LOGGER.error("Exception in callback\nType: %s: %s",
                                    type(err), err)
              self._queue.task_done()
docs: Process callbacks from the queue populated by &listen.