private void readObject(ObjectInputStream stream) throws InvalidObjectException {
    throw new InvalidObjectException("Use SerializedForm");
  }

  /*
   * This class is used to serialize ImmutableEnumSet instances.
   */
  @J2ktIncompatible // serialization
  private static class EnumSerializedForm<E extends Enum<E>> implements Serializable {
    final EnumSet<E> delegate;

  /** Returns the position of an element within the set, or -1 if not present. */
  abstract int indexOf(@CheckForNull Object target);

  /*
   * This class is used to serialize all ImmutableSortedSet instances,
   * regardless of implementation type. It captures their "logical contents"
   * only. This is necessary to ensure that the existence of a particular

   *
   * <p>The returned supplier is thread-safe. The delegate's {@code get()} method will be invoked at
   * most once unless the underlying {@code get()} throws an exception. The supplier's serialized
   * form does not contain the cached value, which will be recalculated when {@code get()} is called
   * on the deserialized instance.
   *

    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

      hashCode = ~~hashCode;
      // needed to deal with GWT integer overflow
    }
    return hashCode;
  }

  /*
   * Serializes ImmutableLists as their logical contents. This ensures that
   * implementation types do not leak into the serialized representation.
   */
  @J2ktIncompatible // serialization
  static class SerializedForm implements Serializable {
    final Object[] elements;

    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
  @J2ktIncompatible // serialization
  @GwtIncompatible // serialization
  Object writeReplace() {
    return super.writeReplace();
  }

  // This class is never actually serialized directly, but we have to make the
  // warning go away (and suppressing would suppress for all nested classes too)
  @J2ktIncompatible // serialization
  private static final long serialVersionUID = 0;

  @GwtIncompatible // SerializableTester
  public void testLexicographicalComparatorSerializable() {
    Comparator<boolean[]> comparator = Booleans.lexicographicalComparator();
    assertThat(SerializableTester.reserialize(comparator)).isSameInstanceAs(comparator);
  }

  public void testReverse() {
    testReverse(new boolean[] {}, new boolean[] {});
    testReverse(new boolean[] {true}, new boolean[] {true});

  @GwtIncompatible // SerializableTester
  public void testLexicographicalComparatorSerializable() {
    Comparator<boolean[]> comparator = Booleans.lexicographicalComparator();
    assertThat(SerializableTester.reserialize(comparator)).isSameInstanceAs(comparator);
  }

  public void testReverse() {
    testReverse(new boolean[] {}, new boolean[] {});
    testReverse(new boolean[] {true}, new boolean[] {true});

    return keySet;
  }

  @Override
  public ImmutableSortedSet<K> descendingKeySet() {
    return keySet.descendingSet();
  }

  /**
   * Serialized type for all ImmutableSortedMap instances. It captures the logical contents and they
   * are reconstructed using public factory methods. This ensures that the implementation types
   * remain as implementation details.
   */