EquivalenceTester.of(Equivalence.equals().onResultOf(Functions.toStringFunction()))
        .addEquivalenceGroup(new IntValue(1), new IntValue(1))
        .addEquivalenceGroup(new IntValue(2))
        .test();
  }

  public void testOnResultOf_equals() {
    new EqualsTester()
        .addEqualityGroup(
            Equivalence.identity().onResultOf(Functions.toStringFunction()),

    EquivalenceTester.of(Equivalence.equals().onResultOf(Functions.toStringFunction()))
        .addEquivalenceGroup(new IntValue(1), new IntValue(1))
        .addEquivalenceGroup(new IntValue(2))
        .test();
  }

  public void testOnResultOf_equals() {
    new EqualsTester()
        .addEqualityGroup(
            Equivalence.identity().onResultOf(Functions.toStringFunction()),

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

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

        Maps.toImmutableEnumMap(Entry::getKey, Entry::getValue);
    Equivalence<ImmutableMap<AnEnum, Integer>> equivalence =
        Equivalence.equals().<Entry<AnEnum, Integer>>pairwise().onResultOf(ImmutableMap::entrySet);
    CollectorTester.of(collector, equivalence)
        .expectCollects(
            ImmutableMap.of(AnEnum.A, 1, AnEnum.C, 2, AnEnum.E, 3),
            mapEntry(AnEnum.A, 1),

  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:
   *
   * <pre>{@code
   * Equivalence<Person> SAME_AGE = Equivalence.equals().onResultOf(GET_PERSON_AGE);
   * }</pre>
   *

   * 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:
   *
   * <pre>{@code
   * Equivalence<Person> SAME_AGE = Equivalence.equals().onResultOf(GET_PERSON_AGE);
   * }</pre>
   *

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

    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 =