code: def get_queue_class(config=None, queue_class=None):
      
      RQ = getattr(settings, 'RQ', {})
      if queue_class is None:
          queue_class = RQ.get('QUEUE_CLASS', DjangoRQ)
          if config:
              queue_class = config.get('QUEUE_CLASS', queue_class)
  
      if isinstance(queue_class, six.string_types):
          queue_class = import_attribute(queue_class)
      return queue_class
docs: Return queue class from config or from RQ settings, otherwise return DjangoRQ.
      If ``queue_class`` is provided, it takes priority.
  
      The full priority list for queue class sources:
      1. ``queue_class`` argument
      2. ``QUEUE_CLASS`` in ``config`` argument
      3. ``QUEUE_CLASS`` in base settings (``RQ``)