import org.checkerframework.checker.nullness.qual.Nullable;

/** Implementation of {@link Futures#immediateFuture}. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
// TODO(cpovirk): Make this final (but that may break Mockito spy calls).
class ImmediateFuture<V extends @Nullable Object> implements ListenableFuture<V> {
  static final ListenableFuture<?> NULL = new ImmediateFuture<@Nullable Object>(null);