List<? extends Future<?>> unused = executor.invokeAll(tasks);
  }

  public void testListeningDecorator() throws Exception {
    ListeningExecutorService service = listeningDecorator(newDirectExecutorService());
    assertThat(listeningDecorator(service)).isSameInstanceAs(service);
    List<Callable<String>> callables = ImmutableList.of(Callables.returning("x"));
    List<Future<String>> results;

    List<? extends Future<?>> unused = executor.invokeAll(tasks);
  }

  public void testListeningDecorator() throws Exception {
    ListeningExecutorService service = listeningDecorator(newDirectExecutorService());
    assertThat(listeningDecorator(service)).isSameInstanceAs(service);
    List<Callable<String>> callables = ImmutableList.of(Callables.returning("x"));
    List<Future<String>> results;

 * from an existing {@link ExecutorService}, call {@link
 * MoreExecutors#listeningDecorator(ExecutorService)}.
 *
 * @author Chris Povirk
 * @since 10.0
 */
@DoNotMock(
    "Use TestingExecutors.sameThreadScheduledExecutor, or wrap a real Executor from "
        + "java.util.concurrent.Executors with MoreExecutors.listeningDecorator")
@GwtIncompatible
public interface ListeningExecutorService extends ExecutorService {
  /**

 * {@code ExecutorService}. Most users should call {@link ListeningExecutorService#submit(Callable)
 * ListeningExecutorService.submit} on a service obtained from {@link
 * MoreExecutors#listeningDecorator}.
 *
 * @author Sven Mawson
 * @since 1.0
 */
@GwtIncompatible
public class ListenableFutureTask<V extends @Nullable Object> extends FutureTask<V>
    implements ListenableFuture<V> {

  @GwtIncompatible // TODO
  public static ListeningExecutorService listeningDecorator(ExecutorService delegate) {
    return (delegate instanceof ListeningExecutorService)
        ? (ListeningExecutorService) delegate
        : (delegate instanceof ScheduledExecutorService)
            ? new ScheduledListeningDecorator((ScheduledExecutorService) delegate)
            : new ListeningDecorator(delegate);
  }

  /**

   * future is {@linkplain Future#isDone() done}.
   *
   * <p>Prefer to create {@code ListenableFuture} instances with {@link SettableFuture}, {@link
   * MoreExecutors#listeningDecorator( java.util.concurrent.ExecutorService)}, {@link
   * ListenableFutureTask}, {@link AbstractFuture}, and other utilities over creating plain {@code
   * Future} instances to be upgraded to {@code ListenableFuture} after the fact.

 * {@code ExecutorService} methods. To create an instance from an existing {@link
 * ScheduledExecutorService}, call {@link
 * MoreExecutors#listeningDecorator(ScheduledExecutorService)}.
 *
 * @author Chris Povirk
 * @since 10.0
 */
@GwtIncompatible
public interface ListeningScheduledExecutorService
    extends ScheduledExecutorService, ListeningExecutorService {

 *       service to a {@link ListeningExecutorService}, usually by calling {@link
 *       MoreExecutors#listeningDecorator(java.util.concurrent.ExecutorService)
 *       MoreExecutors.listeningDecorator}.
 *   <li>If you manually call {@link java.util.concurrent.FutureTask#set} or a similar method,

 *       service to a {@link ListeningExecutorService}, usually by calling {@link
 *       MoreExecutors#listeningDecorator(java.util.concurrent.ExecutorService)
 *       MoreExecutors.listeningDecorator}.
 *   <li>If you manually call {@link java.util.concurrent.FutureTask#set} or a similar method,

import static com.google.common.util.concurrent.Futures.immediateFuture;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static com.google.common.util.concurrent.MoreExecutors.listeningDecorator;
import static com.google.common.util.concurrent.MoreExecutors.shutdownAndAwaitTermination;
import static com.google.common.util.concurrent.Uninterruptibles.awaitUninterruptibly;