implements ScheduledExecutorService {
  final ScheduledExecutorService delegate;

  protected WrappingScheduledExecutorService(ScheduledExecutorService delegate) {
    super(delegate);
    this.delegate = delegate;
  }

  @Override
  public final ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
    return delegate.schedule(wrapTask(command), delay, unit);
  }

  @Override

    return delegate().isDirected();
  }

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

  @Override
  public ElementOrder<N> nodeOrder() {
    return delegate().nodeOrder();
  }

  @Override
  public ElementOrder<N> incidentEdgeOrder() {
    return delegate().incidentEdgeOrder();
  }

  @Override
  public Set<N> adjacentNodes(N node) {

    @ParametricNullness final K key;
    Collection<V> delegate;
    final @Nullable WrappedCollection ancestor;
    final @Nullable Collection<V> ancestorDelegate;

    WrappedCollection(
        @ParametricNullness K key, Collection<V> delegate, @Nullable WrappedCollection ancestor) {
      this.key = key;
      this.delegate = delegate;
      this.ancestor = ancestor;

    delegate.writeTo(sink)
  }

  override fun isDuplex(): Boolean = delegate.isDuplex()

  override fun toString(): String = javaClass.simpleName + "(" + delegate.toString() + ")"

  init {
    requireNotNull(delegate) { "delegate == null" }
    this.delegate = delegate
  }

    return delegate().get(index);
  }

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

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

  @Override
  public ListIterator<E> listIterator() {
    return delegate().listIterator();
  }

  @Override

  private final transient Set<E> delegate;

  ForwardingImmutableSet(Set<E> delegate) {
    // TODO(cpovirk): are we over-wrapping?
    this.delegate = Collections.unmodifiableSet(delegate);
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.unmodifiableIterator(delegate.iterator());
  }

  @Override

  @Override
  public int size() {
    Set<E> delegate = delegateOrNull();
    return (delegate != null) ? delegate.size() : size;
  }

  @Override
  public boolean isEmpty() {
    return size() == 0;
  }

  @Override
  public @Nullable Object[] toArray() {
    if (needsAllocArrays()) {
      return new Object[0];
    }
    Set<E> delegate = delegateOrNull();

@GwtIncompatible
abstract class ForwardingLock implements Lock {
  abstract Lock delegate();

  @Override
  public void lock() {
    delegate().lock();
  }

  @Override
  public void lockInterruptibly() throws InterruptedException {
    delegate().lockInterruptibly();
  }

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

  @Override

  static final ImmutableMap<Object, Object> EMPTY = new RegularImmutableMap<Object, Object>();

  RegularImmutableMap(Map<? extends K, ? extends V> delegate) {
    super(delegate);
  }

  RegularImmutableMap(Entry<? extends K, ? extends V>... entries) {
    this(/* throwIfDuplicateKeys= */ true, entries);
  }

  private InvalidatableSet(
      Set<E> delegate, Supplier<Boolean> validator, Supplier<String> errorMessage) {
    this.delegate = delegate;
    this.validator = validator;
    this.errorMessage = errorMessage;
  }

  // Override hashCode() to access delegate directly (so that it doesn't trigger the validate() call
  // via delegate()); it seems inappropriate to throw ISE on this method.
  @Override
  public int hashCode() {