public boolean hasEmptyPart() {
    // iterator will not contain an empty leaf queue, so check directly
    if (leaf.isEmpty()) {
      return true;
    }

    for (String part : this) {
      if (part.isEmpty()) {
        return true;
      }
    }

    return false;
  }
@Test
  public void testEmptyPart() {
    Assert.assertTrue(QUEUE_PATH_WITH_EMPTY_PART.hasEmptyPart());
    Assert.assertTrue(QUEUE_PATH_WITH_EMPTY_LEAF.hasEmptyPart());
    Assert.assertFalse(TEST_QUEUE_PATH.hasEmptyPart());
  }