static final Serialization.FieldSetter<? super ImmutableMultimap<?, ?>> MAP_FIELD_SETTER =
        Serialization.getFieldSetter(ImmutableMultimap.class, "map");
    static final Serialization.FieldSetter<? super ImmutableMultimap<?, ?>> SIZE_FIELD_SETTER =
        Serialization.getFieldSetter(ImmutableMultimap.class, "size");
  }

  ImmutableMultimap(ImmutableMap<K, ? extends ImmutableCollection<V>> map, int size) {

  }

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(ImmutableMultimap.of(), ImmutableMultimap.of())
        .addEqualityGroup(ImmutableMultimap.of(1, "a"), ImmutableMultimap.of(1, "a"))
        .addEqualityGroup(
            ImmutableMultimap.of(1, "a", 2, "b"), ImmutableMultimap.of(2, "b", 1, "a"))
        .testEquals();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection

  }

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(ImmutableMultimap.of(), ImmutableMultimap.of())
        .addEqualityGroup(ImmutableMultimap.of(1, "a"), ImmutableMultimap.of(1, "a"))
        .addEqualityGroup(
            ImmutableMultimap.of(1, "a", 2, "b"), ImmutableMultimap.of(2, "b", 1, "a"))
        .testEquals();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection

    assertEquals("", j.join(ImmutableMultimap.of().entries()));
    assertEquals("", j.join(ImmutableMultimap.of().entries().iterator()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries().iterator()));
    assertEquals("1:a;1:b", j.join(ImmutableMultimap.of("1", "a", "1", "b").entries()));

          .put(ImmutableSortedMap.class, ImmutableSortedMap.of())
          .put(NavigableMap.class, Maps.unmodifiableNavigableMap(Maps.newTreeMap()))
          .put(Multimap.class, ImmutableMultimap.of())
          .put(ImmutableMultimap.class, ImmutableMultimap.of())
          .put(ListMultimap.class, ImmutableListMultimap.of())
          .put(ImmutableListMultimap.class, ImmutableListMultimap.of())

  }

  public void testInvertFrom() {
    ImmutableMultimap<Integer, String> empty = ImmutableMultimap.of();

    // typical usage example - sad that ArrayListMultimap.create() won't work
    Multimap<String, Integer> multimap =
        Multimaps.invertFrom(empty, ArrayListMultimap.<String, Integer>create());
    assertTrue(multimap.isEmpty());

    ImmutableMultimap<Integer, String> single =

   *
   * <p>Because an inverse of a list multimap can contain multiple pairs with the same key and
   * value, this method returns an {@code ImmutableListMultimap} rather than the {@code
   * ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
   *
   * @since 11.0
   */
  @Override
  public ImmutableListMultimap<V, K> inverse() {
    ImmutableListMultimap<V, K> result = inverse;

          .put(ImmutableSortedMap.class, ImmutableSortedMap.of())
          .put(NavigableMap.class, Maps.unmodifiableNavigableMap(Maps.newTreeMap()))
          .put(Multimap.class, ImmutableMultimap.of())
          .put(ImmutableMultimap.class, ImmutableMultimap.of())
          .put(ListMultimap.class, ImmutableListMultimap.of())
          .put(ImmutableListMultimap.class, ImmutableListMultimap.of())

   *
   * <p>Because an inverse of a set multimap cannot contain multiple pairs with the same key and
   * value, this method returns an {@code ImmutableSetMultimap} rather than the {@code
   * ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
   */
  @Override
  public ImmutableSetMultimap<V, K> inverse() {
    ImmutableSetMultimap<V, K> result = inverse;
    return (result == null) ? (inverse = invert()) : result;
  }

   *
   * <p>Because an inverse of a list multimap can contain multiple pairs with the same key and
   * value, this method returns an {@code ImmutableListMultimap} rather than the {@code
   * ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
   *
   * @since 11.0
   */
  @Override
  public ImmutableListMultimap<V, K> inverse() {
    ImmutableListMultimap<V, K> result = inverse;