* object.
 *
 * <p><b>Comparison to {@code java.util.Optional} (JDK 8 and higher):</b> A new {@code Optional}
 * class was added for Java 8. The two classes are extremely similar, but incompatible (they cannot
 * share a common supertype). <i>All</i> known differences are listed either here or with the
 * relevant methods below.
 *
 * <ul>
 *   <li>This class is serializable; {@code java.util.Optional} is not.

  public static ComparisonChain start() {
    return ACTIVE;
  }

  private static final ComparisonChain ACTIVE =
      new ComparisonChain() {
        @SuppressWarnings("unchecked") // unsafe; see discussion on supertype
        @Override
        public ComparisonChain compare(Comparable<?> left, Comparable<?> right) {
          return classify(((Comparable<Object>) left).compareTo(right));
        }

        @Override

    assertWithMessage("Correct string should be delivered.").that(events.get(0)).isEqualTo(EVENT);
  }

  /**
   * Tests that events are distributed to any subscribers to their type or any supertype, including
   * interfaces and superclasses.
   *
   * <p>Also checks delivery ordering in such cases.
   */
  public void testPolymorphicDistribution() {

    assertWithMessage("Correct string should be delivered.").that(events.get(0)).isEqualTo(EVENT);
  }

  /**
   * Tests that events are distributed to any subscribers to their type or any supertype, including
   * interfaces and superclasses.
   *
   * <p>Also checks delivery ordering in such cases.
   */
  public void testPolymorphicDistribution() {

    EnumBiMap<Currency, Country> bimap1 = EnumBiMap.create(Currency.class, Country.class);
    bimap1.put(Currency.DOLLAR, Country.SWITZERLAND);
    EnumHashBiMap<Currency, Object> bimap2 = // use supertype
        EnumHashBiMap.<Currency, Object>create(bimap1);
    assertEquals(Country.SWITZERLAND, bimap2.get(Currency.DOLLAR));
    assertEquals(bimap1, bimap2);
    bimap2.inverse().put("franc", Currency.FRANC);

 * short}, {@code int}, {@code float}, {@code double}, and {@code long} values.
 *
 * <p><b>Note:</b> This class intentionally violates the specification of its supertype {@code
 * DataInput}, which explicitly requires big-endian byte order.
 *
 * @author Chris Nokleberg
 * @author Keith Bottner
 * @since 8.0
 */
@J2ktIncompatible
@GwtIncompatible

   *
   * @param c the collection for which to return an array of elements
   * @param array the array in which to place the collection elements
   * @throws ArrayStoreException if the runtime type of the specified array is not a supertype of
   *     the runtime type of every element in the specified collection
   */
  static <T extends @Nullable Object> T[] toArrayImpl(Collection<?> c, T[] array) {
    int size = c.size();
    if (array.length < size) {

  public static ComparisonChain start() {
    return ACTIVE;
  }

  private static final ComparisonChain ACTIVE =
      new ComparisonChain() {
        @SuppressWarnings("unchecked") // unsafe; see discussion on supertype
        @Override
        public ComparisonChain compare(Comparable<?> left, Comparable<?> right) {
          return classify(((Comparable<Object>) left).compareTo(right));
        }

        @Override

 * advantage of that for convertAll, as discussed on that method.)
 *
 * 2. The supertype of this class could be `Function<@Nullable A, @Nullable B>`, since
 * Converter.apply (like Converter.convert) is capable of accepting null inputs. However, a
 * supertype of `Function<A, B>` turns out to be massively more useful to callers in practice: They

 * the case. However, most methods from those types are present with the same signature in this
 * class.
 *
 * @param <T> the type that owns this method or constructor.
 * @param <R> the return type of (or supertype thereof) the method or the declaring type of the
 *     constructor.
 * @author Ben Yu
 * @since 14.0 (no longer implements {@link AccessibleObject} or {@code GenericDeclaration} since
 *     31.0)
 */