import org.jspecify.annotations.Nullable;

/**
 * Basic implementation of the {@link SetMultimap} interface. It's a wrapper around {@link
 * AbstractMapBasedMultimap} that converts the returned collections into {@code Sets}. The {@link
 * #createCollection} method must return a {@code Set}.
 *
 * @author Jared Levy
 */
@GwtCompatible
abstract class AbstractSetMultimap<K extends @Nullable Object, V extends @Nullable Object>

    Callable<@Nullable Void> cancelRunnable =
        new Callable<@Nullable Void>() {
          @Override
          public @Nullable Void call() {
            cancellationSuccess.set(currentFuture.get().cancel(true));
            awaitUnchecked(barrier);
            return null;
          }
        };
    Callable<@Nullable Void> setFutureCompleteSuccessfullyRunnable =

  public int compare(@Nullable Object left, @Nullable Object right) {
    return 0;
  }

  @Override
  public <E extends @Nullable Object> List<E> sortedCopy(Iterable<E> iterable) {
    return Lists.newArrayList(iterable);
  }

  @Override
  public <E> ImmutableList<E> immutableSortedCopy(Iterable<E> iterable) {
    return ImmutableList.copyOf(iterable);
  }

    return super.containsAll(collection);
  }

  @Override
  public Iterator<E> iterator() {
    return asList(contents).iterator();
  }

  @Override
  public @Nullable Object[] toArray() {
    @Nullable Object[] result = new @Nullable Object[contents.length];
    arraycopy(contents, 0, result, 0, contents.length);
    return result;
  }

  /*

import org.jspecify.annotations.Nullable;

/** Implementations of {@code Futures.transform*}. */
@GwtCompatible
// Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
@SuppressWarnings("ShortCircuitBoolean")
abstract class AbstractTransformFuture<
        I extends @Nullable Object, O extends @Nullable Object, F, T extends @Nullable Object>

    // ordering.reverse() might be optimized, so let it do its thing
    return ordering.<T>reverse().<@NonNull S>nullsLast();
  }

  @SuppressWarnings("unchecked") // still need the right way to explain this
  @Override
  public <S extends @Nullable T> Ordering<@Nullable S> nullsFirst() {
    return (Ordering<@Nullable S>) this;
  }

  @Override

    private static final AtomicReferenceFieldUpdater<Waiter, @Nullable Thread> waiterThreadUpdater =
        AtomicReferenceFieldUpdater.<Waiter, @Nullable Thread>newUpdater(
            Waiter.class, Thread.class, "thread");
    private static final AtomicReferenceFieldUpdater<Waiter, @Nullable Waiter> waiterNextUpdater =
        AtomicReferenceFieldUpdater.<Waiter, @Nullable Waiter>newUpdater(
            Waiter.class, Waiter.class, "next");

 * invoke methods, they invoke methods on the {@code ForwardingSetMultimap}.
 *
 * @author Kurt Alfred Kluever
 * @since 3.0
 */
@GwtCompatible
public abstract class ForwardingSetMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends ForwardingMultimap<K, V> implements SetMultimap<K, V> {
  /** Constructor for use by subclasses. */
  public ForwardingSetMultimap() {}

  @Override

   *
   * @since 10.0
   */
  public static final class Wrapper<T extends @Nullable Object> implements Serializable {
    /*
     * Equivalence's type argument is always non-nullable: Equivalence<Number>, never
     * Equivalence<@Nullable Number>. That can still produce wrappers of various types --
     * Wrapper<Number>, Wrapper<Integer>, Wrapper<@Nullable Integer>, etc. If we used just

@GwtIncompatible // not worth using in GWT for now
final class CompactLinkedHashMap<K extends @Nullable Object, V extends @Nullable Object>
    extends CompactHashMap<K, V> {
  // TODO(lowasser): implement removeEldestEntry so this can be used as a drop-in replacement

  /** Creates an empty {@code CompactLinkedHashMap} instance. */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      CompactLinkedHashMap<K, V> create() {