return ImmutableSortedSet.naturalOrder();
  }

  @Override
  int getComplexBuilderSetLastElement() {
    return 0x00FFFFFF;
  }

  public void testLegacyComparable_of() {
    ImmutableSortedSet<LegacyComparable> set0 = ImmutableSortedSet.of();
    assertThat(set0).isEmpty();

    @SuppressWarnings("unchecked") // using a legacy comparable