assertEquals(3, function.apply("Three").intValue());

    new EqualsTester()
        .addEqualityGroup(
            function, Functions.forMap(map, 42), SerializableTester.reserialize(function))
        .addEqualityGroup(Functions.forMap(map))
        .addEqualityGroup(Functions.forMap(map, null))
        .addEqualityGroup(Functions.forMap(map, 43))
        .testEquals();
  }

  }

  @CollectionFeature.Require(SERIALIZABLE)
  public void testInverseSerialization() {
    BiMapPair<K, V> pair = new BiMapPair<>(getMap());
    BiMapPair<K, V> copy = SerializableTester.reserialize(pair);
    assertEquals(pair.forward, copy.forward);
    assertEquals(pair.backward, copy.backward);
    assertSame(copy.backward, copy.forward.inverse());
    assertSame(copy.forward, copy.backward.inverse());
  }

    ContainsBothWithMultisetFirst reMultisetFirst = reserialize(multisetFirst);
    assertThat(reMultisetFirst.a.isEmpty()).isFalse();
    // The following NPE is a side effect of our changes to avoid mutating `final` fields.
    assertThrows(NullPointerException.class, () -> reMultisetFirst.z.multiset.isEmpty());

    ContainsBothWithContainsMultisetFirst reContainsMultisetFirst =
        reserialize(containsMultisetFirst);

    assertEquals(HashMultiset.create(multimap.values()), HashMultiset.create(valuesCopy));
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testEmptySerialization() {
    Multimap<String, Integer> multimap = ImmutableListMultimap.of();
    assertSame(multimap, SerializableTester.reserialize(multimap));
  }

  @J2ktIncompatible

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public List<E> create(Object... elements) {
      return (List<E>) SerializableTester.reserialize(gen.create(elements));
    }

    @Override
    public E[] createArray(int length) {
      return gen.createArray(length);
    }

    @Override
    public Iterable<E> order(List<E> insertionOrder) {

    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public Set<E> create(Object... elements) {
      return (Set<E>) SerializableTester.reserialize(gen.create(elements));
    }

    @Override
    public E[] createArray(int length) {
      return gen.createArray(length);
    }

    @Override
    public Iterable<E> order(List<E> insertionOrder) {

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public List<E> create(Object... elements) {
      return (List<E>) SerializableTester.reserialize(gen.create(elements));
    }

    @Override
    public E[] createArray(int length) {
      return gen.createArray(length);
    }

    @Override
    public Iterable<E> order(List<E> insertionOrder) {

    assertEquals(HashMultiset.create(multimap.values()), HashMultiset.create(valuesCopy));
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testEmptySerialization() {
    Multimap<String, Integer> multimap = ImmutableSetMultimap.of();
    assertSame(multimap, SerializableTester.reserialize(multimap));
  }

  @J2ktIncompatible

    Helpers.testComparator(comparator, ordered);
    assertThat(SerializableTester.reserialize(comparator)).isSameInstanceAs(comparator);

    // The Java implementation.
    Comparator<byte[]> javaImpl = UnsignedBytes.lexicographicalComparatorJavaImpl();
    Helpers.testComparator(javaImpl, ordered);
    assertThat(SerializableTester.reserialize(javaImpl)).isSameInstanceAs(javaImpl);
  }

    SerializableTester.reserializeAndAssert(map.entrySet());
    SerializableTester.reserializeAndAssert(map.keySet());
    assertEquals(
        new ArrayList<>(map.values()),
        new ArrayList<>(SerializableTester.reserialize(map.values())));
  }