Optional<String> z = Optional.of("z");

    Comparator<Optional<String>> comparator = emptiesLast(comparing(String::length));
    testComparator(comparator, z, abc, empty);

    // Just demonstrate that no explicit type parameter is required
    Comparator<Optional<String>> unused = emptiesLast(naturalOrder());
  }

  public void testMinMaxNatural() {
    assertThat(min(1, 2)).isEqualTo(1);

   * value.
   *
   * @since 22.0 (but only since 33.4.0 in the Android flavor)
   */
  public static <T> Comparator<Optional<T>> emptiesLast(Comparator<? super T> valueComparator) {
    checkNotNull(valueComparator);
    return Comparator.<Optional<T>, @Nullable T>comparing(
        o -> orElseNull(o), Comparator.nullsLast(valueComparator));
  }