import org.jspecify.annotations.Nullable;

/**
 * A concurrent map which forwards all its method calls to another concurrent map. Subclasses should
 * override one or more methods to modify the behavior of the backing map as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>{@code default} method warning:</b> This class forwards calls to <i>only some</i> {@code

    private final HashBiMap<K, V> forward;

    Inverse(HashBiMap<K, V> forward) {
      this.forward = forward;
    }

    @Override
    public int size() {
      return forward.size;
    }

    @Override
    public boolean containsKey(@Nullable Object key) {
      return forward.containsValue(key);
    }

    @Override

/**
 * {@link FluentFuture} that forwards all calls to a delegate.
 *
 * <h3>Extension</h3>
 *
 * If you want a class like {@code FluentFuture} but with extra methods, we recommend declaring your
 * own subclass of {@link ListenableFuture}, complete with a method like {@link #from} to adapt an
 * existing {@code ListenableFuture}, implemented atop a {@link ForwardingListenableFuture} that
 * forwards to that future and adds the desired methods.

  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())

import org.jspecify.annotations.Nullable;

/**
 * An iterator which forwards all its method calls to another iterator. Subclasses should override
 * one or more methods to modify the behavior of the backing iterator as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>{@code default} method warning:</b> This class forwards calls to <i>only some</i> {@code

    private final NavigableSet<E> forward;

    DescendingSet(NavigableSet<E> forward) {
      this.forward = forward;
    }

    @Override
    protected NavigableSet<E> delegate() {
      return forward;
    }

    @Override
    public @Nullable E lower(@ParametricNullness E e) {
      return forward.higher(e);
    }

    @Override

  public void testFrom() {
    Function<String, Integer> forward =
        new Function<String, Integer>() {
          @Override
          public Integer apply(String input) {
            return Integer.parseInt(input);
          }
        };
    Function<Object, String> backward = toStringFunction();

    Converter<String, Number> converter = Converter.<String, Number>from(forward, backward);

        Thread.sleep(10); // Small delay
        Instant third = MonotonicClock.now();

        assertTrue(first.isBefore(second), "Time should progress forward between measurements");
        assertTrue(second.isBefore(third), "Time should progress forward between measurements");
    }

    @Test
    @DisplayName("MonotonicClock elapsed time should increase")
    void testElapsedTime() throws InterruptedException {