return this == obj;
  }

  @Override
  public int hashCode() {
    return 0x79a31aac;
  }

  @Override
  public String toString() {
    return "Optional.absent()";
  }

  private Object readResolve() {
    return INSTANCE;
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

    @Override
    public Integer minValue() {
      return Integer.MIN_VALUE;
    }

    @Override
    public Integer maxValue() {
      return Integer.MAX_VALUE;
    }

    private Object readResolve() {
      return INSTANCE;
    }

    @Override
    public String toString() {
      return "DiscreteDomain.integers()";
    }

    private static final class SerializedForm<K> implements Serializable {
      final ImmutableMap<K, ?> map;

      SerializedForm(ImmutableMap<K, ?> map) {
        this.map = map;
      }

      Object readResolve() {
        return map.keySet();
      }

      @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
    }
  }

  @Override
  ImmutableCollection<V> createValues() {

    private final DiscreteDomain<C> domain;

    private SerializedForm(DiscreteDomain<C> domain) {
      this.domain = domain;
    }

    private Object readResolve() {
      return new EmptyContiguousSet<>(domain);
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  @GwtIncompatible
  @J2ktIncompatible

    final EnumSet<E> delegate;

    EnumSerializedForm(EnumSet<E> delegate) {
      this.delegate = delegate;
    }

    Object readResolve() {
      // EJ2 #76: Write readObject() methods defensively.
      return new ImmutableEnumSet<E>(delegate.clone());
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

      int i = 0;
      for (Entry<? extends Object> entry : multiset.entrySet()) {
        elements[i] = entry.getElement();
        counts[i] = entry.getCount();
        i++;
      }
    }

    Object readResolve() {
      ImmutableMultiset.Builder<Object> builder =
          new ImmutableMultiset.Builder<Object>(elements.length);
      for (int i = 0; i < elements.length; i++) {
        builder.addCopies(elements[i], counts[i]);

  @Override
  public int compare(Object left, Object right) {
    return left.toString().compareTo(right.toString());
  }

  // preserve singleton-ness, so equals() and hashCode() work correctly
  private Object readResolve() {
    return INSTANCE;
  }

  @Override
  public String toString() {
    return "Ordering.usingToString()";
  }

  private UsingToStringOrdering() {}

   * changes).
   */
  @Override
  public ImmutableMap<Object, Collection<Object>> asMap() {
    return super.asMap();
  }

  private Object readResolve() {
    return INSTANCE; // preserve singleton property
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

  @Override
  public <E extends Comparable<?>> E max(Iterable<E> iterable) {
    return NaturalOrdering.INSTANCE.min(iterable);
  }

  // preserving singleton-ness gives equals()/hashCode() for free
  private Object readResolve() {
    return INSTANCE;
  }

  @Override
  public String toString() {
    return "Ordering.natural().reverse()";
  }

  private ReverseNaturalOrdering() {}

    final EnumSet<E> delegate;

    EnumSerializedForm(EnumSet<E> delegate) {
      this.delegate = delegate;
    }

    Object readResolve() {
      // EJ2 #76: Write readObject() methods defensively.
      return new ImmutableEnumSet<E>(delegate.clone());
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;