@CanIgnoreReturnValue
    boolean set(T t);

    @CanIgnoreReturnValue
    boolean setException(Throwable t);
  }

  private static class NewAbstractFutureFacade<T> extends AbstractFuture<T> implements Facade<T> {
    @CanIgnoreReturnValue
    @Override
    public boolean set(T t) {
      return super.set(t);
    }

    @CanIgnoreReturnValue
    @Override

   *
   * <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.
   */
  public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(

    @CanIgnoreReturnValue
    boolean set(T t);

    @CanIgnoreReturnValue
    boolean setException(Throwable t);
  }

  private static class NewAbstractFutureFacade<T> extends AbstractFuture<T> implements Facade<T> {
    @CanIgnoreReturnValue
    @Override
    public boolean set(T t) {
      return super.set(t);
    }

    @CanIgnoreReturnValue
    @Override

 *   <li>If you manually call {@link java.util.concurrent.FutureTask#set} or a similar method,
 *       create a {@link SettableFuture} instead. (If your needs are more complex, you may prefer
 *       {@link AbstractFuture}.)
 * </ul>
 *
 * <p><b>Test doubles</b>: If you need a {@code ListenableFuture} for your test, try a {@link
 * SettableFuture} or one of the methods in the {@link Futures#immediateFuture Futures.immediate*}

 */

package com.google.common.util.concurrent;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import com.google.common.util.concurrent.AbstractFuture.TrustedFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import org.jspecify.annotations.Nullable;

 *   <li>If you manually call {@link java.util.concurrent.FutureTask#set} or a similar method,
 *       create a {@link SettableFuture} instead. (If your needs are more complex, you may prefer
 *       {@link AbstractFuture}.)
 * </ul>
 *
 * <p><b>Test doubles</b>: If you need a {@code ListenableFuture} for your test, try a {@link
 * SettableFuture} or one of the methods in the {@link Futures#immediateFuture Futures.immediate*}

     *
     * - Any kind of Error from a listener. Even if we could distinguish that case (by exposing some
     * extra state from AbstractFuture), our options are limited: A call to setException() would be
     * a no-op. We could log, but if that's what we really want, we should modify
     * AbstractFuture.executeListener to do so, since that method would have the ability to continue
     * to execute other listeners.
     *

 * FluentFuture.catching} family of methods. Those versions have slightly different signatures.
 */
abstract class GwtFluentFutureCatchingSpecialization<V extends @Nullable Object>
    extends AbstractFuture<V> {
  /*
   * In the GWT versions of the methods (below), every exceptionType parameter is required to be
   * Class<Throwable>. To handle only certain kinds of exceptions under GWT, you'll need to write

 * SettableFuture}).
 *
 * <p>Useful for testing the behavior of Future utilities against odd futures.
 *
 * @author Anthony Zana
 */
@GwtCompatible
@NullUnmarked
final class UncheckedThrowingFuture<V> extends AbstractFuture<V> {

  public static <V> ListenableFuture<V> throwingError(Error error) {
    UncheckedThrowingFuture<V> future = new UncheckedThrowingFuture<V>();
    future.complete(checkNotNull(error));
    return future;
  }

          }
        };
      }
    },
    ABSTRACT_FUTURE {
      @Override
      ExecutionListWrapper newExecutionList() {
        return new ExecutionListWrapper() {
          final AbstractFuture<?> future = new AbstractFuture<Object>() {};

          @Override
          public void add(Runnable runnable, Executor executor) {
            future.addListener(runnable, executor);
          }

          @Override