Set<List<Integer>> degenerate = Sets.cartesianProduct();
    checkHashCode(degenerate);

    checkHashCode(Sets.cartesianProduct(set(1, 2)));

    int num = Integer.MAX_VALUE / 3 * 2; // tickle overflow-related problems
    checkHashCode(Sets.cartesianProduct(set(1, 2, num)));

    Set<Integer> mt = emptySet();
    checkHashCode(Sets.cartesianProduct(mt, mt));

    Integer lastItem = 0;
    for (Integer tmp : mmHeap) {
      lastItem = tmp;
    }
    assertEquals((Integer) 30, lastItem);
  }

  /**
   * This tests a special case where removeAt has to trickle an element first down one level from a
   * min to a max level, then up one level above the index of the removed element. It also tests
   * that skipMe in the iterator plays nicely with forgetMeNot.
   */

      // '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);

    Integer lastItem = 0;
    for (Integer tmp : mmHeap) {
      lastItem = tmp;
    }
    assertEquals((Integer) 30, lastItem);
  }

  /**
   * This tests a special case where removeAt has to trickle an element first down one level from a
   * min to a max level, then up one level above the index of the removed element. It also tests
   * that skipMe in the iterator plays nicely with forgetMeNot.
   */