@Override
   public int size() {
      return 0;
   }
@Test
   public void testIntSpliteratorSplitTryAdvance() {
      Set<Integer> results = new HashSet<>();

      Spliterator.OfInt spliterator = es.intSpliterator();
      Spliterator.OfInt split = spliterator.trySplit();

      assertNull(split);

      IntConsumer consumer = results::add;

      while (spliterator.tryAdvance(consumer)) { }

      assertEquals(0, results.size());
   }