// 'actualLastElement' is now at 'lastElementAt', and the element that was at 'lastElementAt'
      // is now at the end of queue. If that's the element we wanted to remove in the first place,
      // don't try to (incorrectly) trickle it. Instead, just delete it and we're done.
      queue[size] = null;
      return null;
    }
    E toTrickle = elementData(size);
    queue[size] = null;
    MoveDesc<E> changes = fillHole(index, toTrickle);