code: def dq_name(queue_name):
      
      if queue_name.endswith(".DQ"):
          return queue_name
  
      if queue_name.endswith(".XQ"):
          queue_name = queue_name[:-3]
      return queue_name + ".DQ"
docs: Returns the delayed queue name for a given queue.  If the given
      queue name already belongs to a delayed queue, then it is returned
      unchanged.