// Test & Verify
    Iterator<String> i1 = Iterators.consumingIterator(list.iterator());
    Iterator<String> i2 = Iterators.consumingIterator(list.iterator());

    i1.next();
    assertThrows(ConcurrentModificationException.class, () -> i2.next());
  }

  public void testIndexOf_consumedData() {
    Iterator<String> iterator = Lists.newArrayList("manny", "mo", "jack").iterator();