code: def _get_queue(self):
          
          if self._queue is None:
              self._links = []
              queue, depth = self._resolve_queue(self.queue, links=self._links)
              if queue is None and depth > 0:
                  raise QueueLinkBroken
              self._queue = queue
          return self._queue
docs: Gets the actual location of the queue, or None.