@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 long serialVersionUID = 0;
  }

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

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

  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 long serialVersionUID = 0;
  }

  }

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

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

  private Object readResolve() {
    return INSTANCE;
  }

  private static final long serialVersionUID = 0;

  }

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

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

  private Object readResolve() {
    return INSTANCE;
  }

  private static final long serialVersionUID = 0;

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

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

  private static final long serialVersionUID = 0;

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

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

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

    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() {}

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

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

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

    private static final long serialVersionUID = 0;
  }

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

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

  private static final long serialVersionUID = 0;