code: def _worker_run(self):
          
  
          queues = list(self._queue_set)
          random.shuffle(queues)
  
          for queue in queues:
              task_ids, processed_count = self._process_from_queue(queue)
              # Remove queue if queue was processed and was empty
              if not task_ids and processed_count != -1:
                  self._queue_set.remove(queue)
  
              if self._stop_requested:
                  break
              if processed_count > 0:
                  self._did_work = True
  
          if time.time() - self._last_task_check > self.config['SELECT_TIMEOUT'] and \
             not self._stop_requested:
              self._worker_queue_scheduled_tasks()
              self._worker_queue_expired_tasks()
              self._last_task_check = time.time()
docs: Performs one worker run:
          * Processes a set of messages from each queue and removes any empty
            queues from the working set.
          * Move any expired items from the active queue to the queued queue.
          * Move any scheduled items from the scheduled queue to the queued
            queue.