/**
 * The annotated element can be {@code null}.
 *
 * @see Nonnull
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.RUNTIME)

interface IThenable<T extends @Nullable Object> {
  <V extends @Nullable Object> IThenable<V> then(
      @JsOptional @Nullable IThenOnFulfilledCallbackFn<? super T, ? extends V> onFulfilled,
      @JsOptional @Nullable IThenOnRejectedCallbackFn<? extends V> onRejected);

  @JsFunction
  interface IThenOnFulfilledCallbackFn<T extends @Nullable Object, V extends @Nullable Object> {
    V onInvoke(T p0);
  }

  public boolean containsValue(@Nullable Object value) {
    return delegate().containsValue(value);
  }

  @Override
  public @Nullable V get(@Nullable Object rowKey, @Nullable Object columnKey) {
    return delegate().get(rowKey, columnKey);
  }

  @Override
  public boolean isEmpty() {
    return delegate().isEmpty();
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable V put(

    // 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

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

  @Override
  public <S extends @Nullable T> Ordering<@Nullable S> nullsFirst() {
    return ordering.<@NonNull S>nullsFirst();
  }

  @SuppressWarnings("unchecked") // still need the right way to explain this
  @Override

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

  @Override
  public <S extends @Nullable T> Ordering<@Nullable S> nullsFirst() {
    return ordering.<@NonNull S>nullsFirst();
  }

  @SuppressWarnings("unchecked") // still need the right way to explain this
  @Override

    }
  }

  private static <E extends @Nullable Object> E getElementOrThrow(@Nullable Entry<E> entry) {
    if (entry == null) {
      throw new NoSuchElementException();
    }
    return entry.getElement();
  }

  private static <E extends @Nullable Object> @Nullable E getElementOrNull(
      @Nullable Entry<E> entry) {
    return (entry == null) ? null : entry.getElement();
  }

   * would lead to at least slighly more work at startup time.
   */
  @LazyInit private transient @Nullable Ordering<@Nullable Comparable<?>> nullsFirst;
  @LazyInit private transient @Nullable Ordering<@Nullable Comparable<?>> nullsLast;

  @Override
  @SuppressWarnings("unchecked") // TODO(kevinb): the right way to explain this??

import org.jspecify.annotations.Nullable;

abstract class AbstractFutureState<V extends @Nullable Object> extends InternalFutureFailureAccess
    implements ListenableFuture<V> {
  final boolean casListeners(@Nullable Listener expect, Listener update) {
    if (listeners == expect) {
      listeners = update;
      return true;
    }
    return false;
  }

  final @Nullable Listener gasListeners(Listener update) {

  static final class ListFuture<V extends @Nullable Object>
      extends CollectionFuture<V, List<@Nullable V>> {
    ListFuture(
        ImmutableCollection<? extends ListenableFuture<? extends V>> futures,
        boolean allMustSucceed) {
      super(futures, allMustSucceed);
      init();
    }

    @Override
    public List<@Nullable V> combine(List<@Nullable Present<V>> values) {