*/
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Throwables {
  private Throwables() {}

  /**
   * Throws {@code throwable} if it is an instance of {@code declaredType}. Example usage:
   *
   * <pre>
   * for (Foo foo : foos) {
   *   try {
   *     foo.bar();
   *   } catch (BarException | RuntimeException | Error t) {
   *     failure = t;
   *   }
   * }
   * if (failure != null) {

 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Throwables {
  private Throwables() {}

  /**
   * Throws {@code throwable} if it is an instance of {@code declaredType}. Example usage:
   *
   * <pre>
   * for (Foo foo : foos) {
   *   try {
   *     foo.bar();
   *   } catch (BarException | RuntimeException | Error t) {
   *     failure = t;
   *   }
   * }
   * if (failure != null) {

   * ClosingFuture} will be equivalent to this one.
   *
   * <p>If the function throws an exception, that exception is used as the result of the derived
   * {@code ClosingFuture}.
   *
   * <p>Example usage:
   *
   * <pre>{@code
   * ClosingFuture<List<Row>> rowsFuture =
   *     queryFuture.transform((closer, result) -> result.getRows(), executor);
   * }</pre>
   *

   * is present; an empty immutable {@link Set} otherwise.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this method has no equivalent in Java 8's
   * {@code Optional} class. However, this common usage:
   *
   * <pre>{@code
   * for (Foo foo : possibleFoo.asSet()) {
   *   doSomethingWith(foo);
   * }
   * }</pre>
   *
   * ... can be replaced with:
   *
   * <pre>{@code

   * @deprecated <b>Pass parameters of type {@code Comparable} to use {@link
   *     ImmutableSortedSet#copyOf(Comparable[])}.</b>
   */
  @DoNotCall("Pass parameters of type Comparable")
  @Deprecated
  // The usage of "Z" here works around bugs in Javadoc (JDK-8318093) and JDiff.
  public static <Z> ImmutableSortedSet<Z> copyOf(Z[] elements) {
    throw new UnsupportedOperationException();
  }

   * if the primary input succeeds, it is never invoked. If, during the invocation of {@code
   * fallback}, an exception is thrown, this exception is used as the result of the output {@code
   * Future}.
   *
   * <p>Usage example:
   *
   * <pre>{@code
   * ListenableFuture<Integer> fetchCounterFuture = ...;
   *
   * // Falling back to a zero counter in case an exception happens when
   * // processing the RPC to fetch counters.

/**
 * A {@link Collection} whose contents will never change, and which offers a few additional
 * guarantees detailed below.
 *
 * <p><b>Warning:</b> avoid <i>direct</i> usage of {@link ImmutableCollection} as a type (just as
 * with {@link Collection} itself). Prefer subtypes such as {@link ImmutableSet} or {@link

/**
 * A {@link Collection} whose contents will never change, and which offers a few additional
 * guarantees detailed below.
 *
 * <p><b>Warning:</b> avoid <i>direct</i> usage of {@link ImmutableCollection} as a type (just as
 * with {@link Collection} itself). Prefer subtypes such as {@link ImmutableSet} or {@link

   * is present; an empty immutable {@link Set} otherwise.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this method has no equivalent in Java 8's
   * {@code Optional} class. However, this common usage:
   *
   * <pre>{@code
   * for (Foo foo : possibleFoo.asSet()) {
   *   doSomethingWith(foo);
   * }
   * }</pre>
   *
   * ... can be replaced with:
   *
   * <pre>{@code

   * Executor#execute execute}, as in {@code ThreadPoolExecutor.CallerRunsPolicy}.
   *
   * <p>This executor is appropriate for tasks that are lightweight and not deeply chained.
   * Inappropriate {@code directExecutor} usage can cause problems, and these problems can be
   * difficult to reproduce because they depend on timing. For example:
   *
   * <ul>
   *   <li>When a {@code ListenableFuture} listener is registered to run under {@code