*/
@GwtCompatible
@ElementTypesAreNonnullByDefault
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
  public void addListener(Runnable listener, Executor exec) {

  @J2ktIncompatible
  @GwtIncompatible // PriorityBlockingQueue
  public static <E extends Comparable> PriorityBlockingQueue<E> newPriorityBlockingQueue(
      Iterable<? extends E> elements) {
    if (elements instanceof Collection) {
      return new PriorityBlockingQueue<>((Collection<? extends E>) elements);
    }
    PriorityBlockingQueue<E> queue = new PriorityBlockingQueue<>();

public abstract class AbstractImmutableSetTest extends TestCase {

  protected abstract <E extends Comparable<? super E>> Set<E> of();

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e);

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e1, E e2);

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3);

    multiset.add("a");
    assertThrows(UnsupportedOperationException.class, () -> multiset.remove("a"));
    assertTrue(multiset.contains("a"));
  }

  private static class NoRemoveMultiset<E extends @Nullable Object> extends AbstractMultiset<E>
      implements Serializable {
    final Map<E, Integer> backingMap = Maps.newHashMap();

    @Override
    public int size() {
      return Multisets.linearTimeSizeImpl(this);

   */
  public interface FunctionWithIndex<T extends @Nullable Object, R extends @Nullable Object> {
    /** Applies this function to the given argument and its index within a stream. */
    @ParametricNullness
    R apply(@ParametricNullness T from, long index);
  }

  private abstract static class MapWithIndexSpliterator<
          F extends Spliterator<?>,
          R extends @Nullable Object,

@ElementTypesAreNonnullByDefault
public abstract class AbstractListeningExecutorService extends AbstractExecutorService
    implements ListeningExecutorService {

  /**
   * @since 19.0 (present with return type {@code ListenableFutureTask} since 14.0)
   */
  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override
  protected final <T extends @Nullable Object> RunnableFuture<T> newTaskFor(

@ElementTypesAreNonnullByDefault
public abstract class AbstractListeningExecutorService extends AbstractExecutorService
    implements ListeningExecutorService {

  /**
   * @since 19.0 (present with return type {@code ListenableFutureTask} since 14.0)
   */
  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override
  protected final <T extends @Nullable Object> RunnableFuture<T> newTaskFor(

/** An ordering that treats {@code null} as less than all other values. */
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
final class NullsFirstOrdering<T extends @Nullable Object> extends Ordering<@Nullable T>
    implements Serializable {
  final Ordering<? super T> ordering;

  NullsFirstOrdering(Ordering<? super T> ordering) {
    this.ordering = ordering;
  }

  @Override

     * @since 19.0
     */
    @CanIgnoreReturnValue
    public Builder<K, V> putAll(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
      if (entries instanceof Collection) {
        ensureCapacity(size + ((Collection<?>) entries).size());
      }
      for (Entry<? extends K, ? extends V> entry : entries) {
        put(entry);
      }
      return this;
    }

    /**

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@ElementTypesAreNonnullByDefault
public abstract class AbstractMultimapTester<
        K extends @Nullable Object, V extends @Nullable Object, M extends Multimap<K, V>>
    extends AbstractContainerTester<M, Entry<K, V>> {

  private M multimap;

  protected M multimap() {
    return multimap;
  }

  /**