values.removeAll(Lists.newArrayList(2));
    assertEquals(values.size(), mmHeap.size());
    assertTrue(values.containsAll(mmHeap));
    assertTrue(mmHeap.containsAll(values));
  }

  public void testIteratorInvalidatingIteratorRemove() {
    MinMaxPriorityQueue<Integer> mmHeap = MinMaxPriorityQueue.create();
    mmHeap.addAll(Lists.newArrayList(1, 20, 100, 2, 3, 30, 40));
    assertEquals(7, mmHeap.size());