queue[size] = null;
      return null;
    }
    E actualLastElement = elementData(size);
    int lastElementAt = heapForIndex(size).swapWithConceptuallyLastElement(actualLastElement);
    if (lastElementAt == index) {
      // '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,