*
 * @author Shardul Deo
 * @since 4.0
 */
@GwtCompatible
public abstract class ForwardingListenableFuture<V extends @Nullable Object>
    extends ForwardingFuture<V> implements ListenableFuture<V> {

  /** Constructor for use by subclasses. */
  protected ForwardingListenableFuture() {}

  @Override
  protected abstract ListenableFuture<? extends V> delegate();

  @Override

 *
 * @author Shardul Deo
 * @since 4.0
 */
@GwtCompatible
public abstract class ForwardingListenableFuture<V extends @Nullable Object>
    extends ForwardingFuture<V> implements ListenableFuture<V> {

  /** Constructor for use by subclasses. */
  protected ForwardingListenableFuture() {}

  @Override
  protected abstract ListenableFuture<? extends V> delegate();

  @Override

 * own subclass of {@link ListenableFuture}, complete with a method like {@link #from} to adapt an
 * existing {@code ListenableFuture}, implemented atop a {@link ForwardingListenableFuture} that
 * forwards to that future and adds the desired methods.
 */
@GwtCompatible
final class ForwardingFluentFuture<V extends @Nullable Object> extends FluentFuture<V> {

 * own subclass of {@link ListenableFuture}, complete with a method like {@link #from} to adapt an
 * existing {@code ListenableFuture}, implemented atop a {@link ForwardingListenableFuture} that
 * forwards to that future and adds the desired methods.
 */
@GwtCompatible
final class ForwardingFluentFuture<V extends @Nullable Object> extends FluentFuture<V> {

import static java.util.concurrent.Executors.callable;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.common.util.concurrent.ForwardingListenableFuture.SimpleForwardingListenableFuture;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListenableScheduledFuture;

import static java.util.concurrent.Executors.callable;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.common.util.concurrent.ForwardingListenableFuture.SimpleForwardingListenableFuture;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListenableScheduledFuture;

import static com.google.common.util.concurrent.Uninterruptibles.awaitUninterruptibly;
import static org.junit.Assert.assertThrows;

import com.google.common.util.concurrent.ForwardingListenableFuture.SimpleForwardingListenableFuture;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Function;
import com.google.common.util.concurrent.ForwardingListenableFuture.SimpleForwardingListenableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;

import static com.google.common.util.concurrent.Uninterruptibles.awaitUninterruptibly;
import static org.junit.Assert.assertThrows;

import com.google.common.util.concurrent.ForwardingListenableFuture.SimpleForwardingListenableFuture;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Supplier;
import com.google.common.collect.Lists;
import com.google.common.collect.Queues;
import com.google.common.util.concurrent.ForwardingListenableFuture.SimpleForwardingListenableFuture;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.lang.reflect.InvocationTargetException;
import java.time.Duration;
import java.util.Collection;