* PeekingIterator#remove()} removes the same elements as the reference's iterator {@code
   * remove()}.
   */
  private static class PeekingIteratorTester<T extends @Nullable Object> extends IteratorTester<T> {
    private final Iterable<T> master;
    private @Nullable List<T> targetList;

    PeekingIteratorTester(Collection<T> master) {
      super(master.size() + 3, MODIFIABLE, master, IteratorTester.KnownOrder.KNOWN_ORDER);

 *
 * @author Louis Wasserman
 */
@GwtIncompatible // not worth using in GWT for now
final class CompactLinkedHashSet<E extends @Nullable Object> extends CompactHashSet<E> {

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {
    return new CompactLinkedHashSet<>();
  }

  /**

 *
 * @author Louis Wasserman
 */
@GwtIncompatible // not worth using in GWT for now
final class CompactLinkedHashSet<E extends @Nullable Object> extends CompactHashSet<E> {

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {
    return new CompactLinkedHashSet<>();
  }

  /**

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@link AbstractCache}.
 *
 * @author Charles Fry
 */
@NullUnmarked
public class AbstractCacheTest extends TestCase {

  public void testGetIfPresent() {

  @Override
  @ParametricNullness
  public <T extends @Nullable Object> T callWithTimeout(
      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit) throws ExecutionException {
    checkNotNull(callable);
    checkNotNull(timeoutUnit);
    try {
      return callable.call();
    } catch (RuntimeException e) {
      throw new UncheckedExecutionException(e);

import java.util.concurrent.Future;
import org.jspecify.annotations.Nullable;

/**
 * Transforms a value, possibly asynchronously. For an example usage and more information, see
 * {@link Futures#transformAsync(ListenableFuture, AsyncFunction, Executor)}.
 *
 * @author Chris Povirk
 * @since 11.0
 */
@GwtCompatible
public interface AsyncFunction<I extends @Nullable Object, O extends @Nullable Object> {
  /**

package com.google.common.util.concurrent;

import static com.google.common.collect.Sets.newHashSet;

import java.util.Set;
import org.jspecify.annotations.Nullable;

/** Emulation of AggregateFutureState. */
abstract class AggregateFutureState<OutputT extends @Nullable Object>
    extends AbstractFuture.TrustedFuture<OutputT> {
  // Lazily initialized the first time we see an exception; not released until all the input futures

            DefaultVersionResolverRequest(
                    @Nonnull Session session,
                    @Nullable RequestTrace trace,
                    @Nonnull ArtifactCoordinates artifactCoordinates,
                    @Nullable List<RemoteRepository> repositories) {
                super(session, trace);
                this.artifactCoordinates = artifactCoordinates;

  public void testWildcardFuture() {
    SettableFuture<String> settable = SettableFuture.create();
    ListenableFuture<?> f = settable;
    FutureCallback<@Nullable Object> callback =
        new FutureCallback<@Nullable Object>() {
          @Override
          public void onSuccess(@Nullable Object result) {}

          @Override
          public void onFailure(Throwable t) {}
        };
    addCallback(f, callback, directExecutor());

 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingMultiset<E extends @Nullable Object> extends ForwardingCollection<E>
    implements Multiset<E> {

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

  @Override
  protected abstract Multiset<E> delegate();

  @Override
  public int count(@Nullable Object element) {
    return delegate().count(element);
  }