* non-null objects {@code x} and {@code y}, {@code equivalence.onResultOf(function).equivalent(a,
   * b)} is true if and only if {@code equivalence.equivalent(function.apply(a), function.apply(b))}
   * is true.
   *
   * <p>For example:
   *
   * {@snippet :
   * Equivalence<Person> SAME_AGE = Equivalence.equals().onResultOf(GET_PERSON_AGE);
   * }
   *

            comparator, DECREASING_INTEGER.onResultOf(StringLengthFunction.STRING_LENGTH))
        .addEqualityGroup(DECREASING_INTEGER.onResultOf(Functions.constant(1)))
        .addEqualityGroup(Ordering.natural())
        .testEquals();
    reserializeAndAssert(comparator);
    assertThat(comparator.toString())
        .isEqualTo("Ordering.natural().reverse().onResultOf(STRING_LENGTH)");
  }

            comparator, DECREASING_INTEGER.onResultOf(StringLengthFunction.STRING_LENGTH))
        .addEqualityGroup(DECREASING_INTEGER.onResultOf(Functions.constant(1)))
        .addEqualityGroup(Ordering.natural())
        .testEquals();
    reserializeAndAssert(comparator);
    assertThat(comparator.toString())
        .isEqualTo("Ordering.natural().reverse().onResultOf(STRING_LENGTH)");
  }

    BiPredicate<ImmutableSortedMap<String, Integer>, ImmutableSortedMap<String, Integer>>
        equivalence =
            Equivalence.equals()
                .onResultOf(ImmutableSortedMap<String, Integer>::comparator)
                .and(Equivalence.equals().onResultOf(map -> map.entrySet().asList()))
                .and(Equivalence.equals());
    ImmutableSortedMap<String, Integer> expected =

  private static final Ordering<List<Class<?>>> ORDERING_BY_CONSTRUCTOR_PARAMETER_LIST =
      Ordering.natural()
          .onResultOf((List<Class<?>> params) -> params.contains(String.class))
          .compound(
              Ordering.natural()
                  .onResultOf((List<Class<?>> params) -> params.contains(Throwable.class)))
          .reverse();

   * non-null objects {@code x} and {@code y}, {@code equivalence.onResultOf(function).equivalent(a,
   * b)} is true if and only if {@code equivalence.equivalent(function.apply(a), function.apply(b))}
   * is true.
   *
   * <p>For example:
   *
   * {@snippet :
   * Equivalence<Person> SAME_AGE = Equivalence.equals().onResultOf(GET_PERSON_AGE);
   * }
   *

   *
   * {@snippet :
   * Ordering.from(String.CASE_INSENSITIVE_ORDER).onResultOf(Functions.toStringFunction())
   * }
   *
   * <p><b>Java 8+ users:</b> Use {@code Comparator.comparing(function, thisComparator)} instead
   * (you can omit the comparator if it is the natural order).
   */
  public <F extends @Nullable Object> Ordering<F> onResultOf(Function<F, ? extends T> function) {
    return new ByFunctionOrdering<>(function, this);

   *
   * {@snippet :
   * Ordering.from(String.CASE_INSENSITIVE_ORDER).onResultOf(Functions.toStringFunction())
   * }
   *
   * <p><b>Java 8+ users:</b> Use {@code Comparator.comparing(function, thisComparator)} instead
   * (you can omit the comparator if it is the natural order).
   */
  public <F extends @Nullable Object> Ordering<F> onResultOf(Function<F, ? extends T> function) {
    return new ByFunctionOrdering<>(function, this);

        toImmutableSetMultimap(Entry::getKey, Entry::getValue);
    BiPredicate<ImmutableSetMultimap<?, ?>, ImmutableSetMultimap<?, ?>> equivalence =
        Equivalence.equals()
            .onResultOf(
                (ImmutableSetMultimap<?, ?> mm) ->
                    ImmutableListMultimap.copyOf(mm).asMap().entrySet().asList())
            .and(Equivalence.equals());
    CollectorTester.of(collector, equivalence)

        toImmutableListMultimap(Entry::getKey, Entry::getValue);
    BiPredicate<ImmutableListMultimap<?, ?>, ImmutableListMultimap<?, ?>> equivalence =
        Equivalence.equals()
            .onResultOf((ImmutableListMultimap<?, ?> mm) -> mm.asMap().entrySet().asList())
            .and(Equivalence.equals());
    CollectorTester.of(collector, equivalence)
        .expectCollects(ImmutableListMultimap.of())