* the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSortedMultiset} forward
 * <b>indiscriminately</b> to the methods of the delegate. For example, overriding {@link
 * #add(Object, int)} alone <b>will not</b> change the behavior of {@link #add(Object)}, which can

 * more methods to modify the behavior of the backing queue as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingQueue} forward <b>indiscriminately</b> to the
 * methods of the delegate. For example, overriding {@link #add} alone <b>will not</b> change the
 * behavior of {@link #offer} which can lead to unexpected behavior. In this case, you should

   * forward to this implementation.
   */
  protected @Nullable Entry<K, V> standardFirstEntry() {
    return Iterables.<@Nullable Entry<K, V>>getFirst(entrySet(), null);
  }

  /**
   * A sensible definition of {@link #firstKey} in terms of {@code firstEntry}. If you override
   * {@code firstEntry}, you may wish to override {@code firstKey} to forward to this
   * implementation.
   */

   * forward to this implementation.
   */
  protected @Nullable Entry<K, V> standardFirstEntry() {
    return Iterables.<@Nullable Entry<K, V>>getFirst(entrySet(), null);
  }

  /**
   * A sensible definition of {@link #firstKey} in terms of {@code firstEntry}. If you override
   * {@code firstEntry}, you may wish to override {@code firstKey} to forward to this
   * implementation.
   */

 * <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSortedSet} forward <i>indiscriminately</i> to
 * the methods of the delegate. For example, overriding {@link #add} alone <i>will not</i> change
 * the behavior of {@link #addAll}, which can lead to unexpected behavior. In this case, you should

 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingNavigableSet} forward <i>indiscriminately</i>
 * to the methods of the delegate. For example, overriding {@link #add} alone <i>will not</i> change
 * the behavior of {@link #addAll}, which can lead to unexpected behavior. In this case, you should

   * forward to this implementation.
   *
   * @since 7.0
   */
  protected int standardHashCode() {
    return Sets.hashCodeImpl(entrySet());
  }

  /**
   * A sensible definition of {@link #toString} in terms of the {@code iterator} method of {@link
   * #entrySet}. If you override {@link #entrySet}, you may wish to override {@link #toString} to
   * forward to this implementation.
   *

  private static final class InverseSerializedForm<K, V> implements Serializable {
    private final ImmutableBiMap<K, V> forward;

    InverseSerializedForm(ImmutableBiMap<K, V> forward) {
      this.forward = forward;
    }

    Object readResolve() {
      return forward.inverse();
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 1;
  }

    BiMapPair<K, V> copy = SerializableTester.reserialize(pair);
    assertEquals(pair.forward, copy.forward);
    assertEquals(pair.backward, copy.backward);
    assertSame(copy.backward, copy.forward.inverse());
    assertSame(copy.forward, copy.backward.inverse());
  }

  private static final class BiMapPair<K, V> implements Serializable {
    final BiMap<K, V> forward;
    final BiMap<V, K> backward;

    BiMapPair(BiMap<K, V> original) {

            Currency.FRANC, Country.SWITZERLAND);
    EnumBiMap<Currency, Country> bimap = EnumBiMap.create(map);

    // forward map ordered by currency
    assertThat(bimap.keySet())
        .containsExactly(Currency.DOLLAR, Currency.FRANC, Currency.PESO)
        .inOrder();
    // forward map ordered by currency (even for country values)
    assertThat(bimap.values())