code: def loop_stop(self, force=False):
          
          if self._thread is None:
              return MQTT_ERR_INVAL
  
          self._thread_terminate = True
          self._thread.join()
          self._thread = None
docs: This is part of the threaded client interface. Call this once to
          stop the network thread previously created with loop_start(). This call
          will block until the network thread finishes.
  
          The force parameter is currently ignored.