final EnumMap<K, V> delegate;

    EnumSerializedForm(EnumMap<K, V> delegate) {
      this.delegate = delegate;
    }

    Object readResolve() {
      return new ImmutableEnumMap<>(delegate);
    }

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

  public <S extends Comparable<?>> Ordering<S> reverse() {
    return (Ordering<S>) ReverseNaturalOrdering.INSTANCE;
  }

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

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

  private NaturalOrdering() {}

    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() {

    final ImmutableMap<K, V> map;

    EntrySetSerializedForm(ImmutableMap<K, V> map) {
      this.map = map;
    }

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

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

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

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

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

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

  public <S extends Comparable<?>> Ordering<S> reverse() {
    return (Ordering<S>) ReverseNaturalOrdering.INSTANCE;
  }

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

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

  private NaturalOrdering() {}

    final ImmutableMap<K, V> map;

    EntrySetSerializedForm(ImmutableMap<K, V> map) {
      this.map = map;
    }

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

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

    private final Map<Class<? extends @NonNull B>, B> backingMap;

    SerializedForm(Map<Class<? extends @NonNull B>, B> backingMap) {
      this.backingMap = backingMap;
    }

    Object readResolve() {
      return create(backingMap);
    }

    private static final long serialVersionUID = 0;
  }

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

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

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

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

    private final DiscreteDomain<C> domain;

    AsSetSerializedForm(ImmutableList<Range<C>> ranges, DiscreteDomain<C> domain) {
      this.ranges = ranges;
      this.domain = domain;
    }

    Object readResolve() {
      return new ImmutableRangeSet<C>(ranges).asSet(domain);
    }
  }

  /**
   * Returns {@code true} if this immutable range set's implementation contains references to