*
 * @author Jared Levy
 */
@GwtCompatible
@SuppressWarnings("serial") // we're overriding default serialization
final class ImmutableEnumSet<E extends Enum<E>> extends ImmutableSet<E> {
  static <E extends Enum<E>> ImmutableSet<E> asImmutable(EnumSet<E> set) {
    switch (set.size()) {
      case 0:
        return ImmutableSet.of();
      case 1:
        return ImmutableSet.of(getOnlyElement(set));

 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public class ListenableFutureTask<V extends @Nullable Object> extends FutureTask<V>
    implements ListenableFuture<V> {
  // TODO(cpovirk): explore ways of making ListenableFutureTask final. There are some valid reasons
  // such as BoundedQueueExecutorService to allow extends but it would be nice to make it final to
  // avoid unintended usage.

  public final ImmutableList<TypeToken<? extends Throwable>> getExceptionTypes() {
    ImmutableList.Builder<TypeToken<? extends Throwable>> builder = ImmutableList.builder();
    for (Type type : getGenericExceptionTypes()) {
      // getGenericExceptionTypes() will never return a type that's not exception
      @SuppressWarnings("unchecked")
      TypeToken<? extends Throwable> exceptionType =

 * #createCollection} method must return a {@code List}.
 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
abstract class AbstractListMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMapBasedMultimap<K, V> implements ListMultimap<K, V> {
  /**
   * Creates a new multimap that uses the provided map.
   *

  }

  @Override
  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
      throws InterruptedException {
    Preconditions.checkNotNull(tasks, "tasks must not be null!");
    return delegate.invokeAll(tasks);
  }

  @Override
  public <T> List<Future<T>> invokeAll(
      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
      throws InterruptedException {

  }

  @Override
  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
      throws InterruptedException {
    Preconditions.checkNotNull(tasks, "tasks must not be null!");
    return delegate.invokeAll(tasks);
  }

  @Override
  public <T> List<Future<T>> invokeAll(
      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
      throws InterruptedException {

 * elements.
 */
@GwtCompatible
final class ByFunctionOrdering<F extends @Nullable Object, T extends @Nullable Object>
    extends Ordering<F> implements Serializable {
  final Function<F, ? extends T> function;
  final Ordering<T> ordering;

  ByFunctionOrdering(Function<F, ? extends T> function, Ordering<T> ordering) {
    this.function = checkNotNull(function);

/**
 * Implementation of {@link Multimaps#filterKeys(SetMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredKeySetMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends FilteredKeyMultimap<K, V> implements FilteredSetMultimap<K, V> {

  FilteredKeySetMultimap(SetMultimap<K, V> unfiltered, Predicate<? super K> keyPredicate) {
    super(unfiltered, keyPredicate);
  }

import java.io.Serializable;
import org.jspecify.annotations.Nullable;

/** An ordering that uses the natural order of the values. */
@GwtCompatible
final class NaturalOrdering extends Ordering<Comparable<?>> implements Serializable {
  static final NaturalOrdering INSTANCE = new NaturalOrdering();

  // TODO: b/287198172 - Consider eagerly initializing these (but think about serialization).

@J2ktIncompatible
@GwtIncompatible
public abstract class ForwardingListeningExecutorService extends ForwardingExecutorService
    implements ListeningExecutorService {
  /** Constructor for use by subclasses. */
  protected ForwardingListeningExecutorService() {}

  @Override
  protected abstract ListeningExecutorService delegate();

  @Override
  public <T extends @Nullable Object> ListenableFuture<T> submit(Callable<T> task) {