/** Constructor for use by subclasses. */
  protected ForwardingNavigableSet() {}

  @Override
  protected abstract NavigableSet<E> delegate();

  @Override
  @CheckForNull
  public E lower(@ParametricNullness E e) {
    return delegate().lower(e);
  }

  /**
   * A sensible definition of {@link #lower} in terms of the {@code descendingIterator} method of

        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

  private static <K, V> Multimap<K, V> wrap(final Multimap<K, V> delegate) {
    return new ForwardingMultimap<K, V>() {
      @Override
      protected Multimap<K, V> delegate() {
        return delegate;
      }
    };
  }

  private static class SimpleForwardingSortedMap<K, V> extends ForwardingSortedMap<K, V> {
    final SortedMap<K, V> delegate;

    SimpleForwardingSortedMap(SortedMap<K, V> delegate) {
      this.delegate = delegate;
    }

    @Override
    protected SortedMap<K, V> delegate() {
      return delegate;
    }
  }

  public ForwardingSortedMapImplementsMapTest() {
    super(true, true, true, true, true);
  }

  @Override
  protected abstract Queue<E> delegate();

  @CanIgnoreReturnValue // TODO(cpovirk): Consider removing this?
  @Override
  public boolean offer(@ParametricNullness E o) {
    return delegate().offer(o);
  }

  @CanIgnoreReturnValue // TODO(cpovirk): Consider removing this?
  @Override
  @CheckForNull
  public E poll() {
    return delegate().poll();
  }

  @CanIgnoreReturnValue
  @Override

  protected ForwardingSortedSetMultimap() {}

  @Override
  protected abstract SortedSetMultimap<K, V> delegate();

  @Override
  public SortedSet<V> get(@ParametricNullness K key) {
    return delegate().get(key);
  }

  @Override
  public SortedSet<V> removeAll(@CheckForNull Object key) {
    return delegate().removeAll(key);
  }

  @Override

  @Override
  protected abstract SortedSet<E> delegate();

  @Override
  @CheckForNull
  public Comparator<? super E> comparator() {
    return delegate().comparator();
  }

  @Override
  @ParametricNullness
  public E first() {
    return delegate().first();
  }

  @Override
  public SortedSet<E> headSet(@ParametricNullness E toElement) {
    return delegate().headSet(toElement);
  }

  @Override

  static <V extends @Nullable Object> ListenableFuture<V> create(
      ListenableFuture<V> delegate,
      long time,
      TimeUnit unit,
      ScheduledExecutorService scheduledExecutor) {
    TimeoutFuture<V> result = new TimeoutFuture<>(delegate);
    Fire<V> fire = new Fire<>(result);
    result.timer = scheduledExecutor.schedule(fire, time, unit);
    delegate.addListener(fire, directExecutor());
    return result;
  }

  /*

import okio.Buffer
import okio.ForwardingSink
import okio.Sink

/** A sink that never throws IOExceptions, even if the underlying sink does. */
internal open class FaultHidingSink(
  delegate: Sink,
  val onException: (IOException) -> Unit,
) : ForwardingSink(delegate) {
  private var hasErrors = false

  override fun write(
    source: Buffer,
    byteCount: Long,
  ) {
    if (hasErrors) {
      source.skip(byteCount)

  @Override
  protected abstract ConcurrentMap<K, V> delegate();

  @CanIgnoreReturnValue
  @Override
  @CheckForNull
  public V putIfAbsent(K key, V value) {
    return delegate().putIfAbsent(key, value);
  }

  @CanIgnoreReturnValue
  @Override
  public boolean remove(@CheckForNull Object key, @CheckForNull Object value) {
    return delegate().remove(key, value);
  }

  @CanIgnoreReturnValue
  @Override

    this(new TreeMap<K, V>(map));
  }

  private SafeTreeMap(NavigableMap<K, V> delegate) {
    this.delegate = delegate;
    if (delegate == null) {
      throw new NullPointerException();
    }
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

  @Override