Ptr<const WifiMacQueueItem> item = m_queue->Peek ();

              m_queue->Remove ();

              if (item)

                {

                  packet = item->GetPacket ();

                  header = item->GetHeader ();

                }

  for (auto it = Head (); it != Tail (); )

  Ptr<WifiMacQueueItem> item = DoRemove (Head ());

    {

      if (!TtlExceeded (it))

  for (auto it = Head (); it != Tail () && TtlExceeded (it); );

        {

          return DoRemove (it);

  return item;

        }

    }

  NS_LOG_DEBUG ("The queue is empty");

  return 0;