// release
                old.release(true);
            }
            if (this.delegate != null && this.delegateAcquired) {
                log.debug("Releasing delegate");
                this.delegateAcquired = false;
                this.delegate.release();
            }
        }
    }

    /**
     * @return tree connection with increased usage count
     */

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

  @CanIgnoreReturnValue
  @Override
  public int drainTo(Collection<? super E> c, int maxElements) {
    return delegate().drainTo(c, maxElements);
  }

  @CanIgnoreReturnValue
  @Override
  public int drainTo(Collection<? super E> c) {
    return delegate().drainTo(c);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this

   *
   * <p>If {@code delegate} is an instance created by an earlier call to {@code memoize}, it is
   * returned directly.
   */
  public static <T extends @Nullable Object> Supplier<T> memoize(Supplier<T> delegate) {
    if (delegate instanceof NonSerializableMemoizingSupplier
        || delegate instanceof MemoizingSupplier) {
      return delegate;
    }
    return delegate instanceof Serializable

                    + " the delegate) instead of forwarding to delegate.close()");
          }
        };
    ExecutorService wrapper =
        new ForwardingExecutorService() {
          @Override
          protected ExecutorService delegate() {
            return delegate;
          }
        };
    Method closeMethod;
    try {

              public ListIterator<?> apply(ListIterator delegate) {
                return wrap((ListIterator<?>) delegate);
              }
            });
  }

  private static <T> ListIterator<T> wrap(ListIterator<T> delegate) {
    return new ForwardingListIterator<T>() {
      @Override
      protected ListIterator<T> delegate() {
        return delegate;
      }
    };
  }

      e = null,
    )
  }

  /** A request body that fires events when it completes. */
  private inner class RequestBodySink(
    delegate: Sink,
    /** The exact number of bytes to be written, or -1L if that is unknown. */
    private val contentLength: Long,
  ) : ForwardingSink(delegate) {
    private var completed = false
    private var bytesReceived = 0L
    private var closed = false

    @Throws(IOException::class)

  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

  public static final class NavigableSetSubsetTestSetGenerator<E>
      extends SortedSetSubsetTestSetGenerator<E> {
    public NavigableSetSubsetTestSetGenerator(
        TestSortedSetGenerator<E> delegate, Bound to, Bound from) {
      super(delegate, to, from);
    }

    @Override
    NavigableSet<E> createSubSet(SortedSet<E> sortedSet, E firstExclusive, E lastExclusive) {
      NavigableSet<E> set = (NavigableSet<E>) sortedSet;

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

  @Override
  public void add(@ParametricNullness E element) {
    delegate().add(element);
  }

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

  @Override
  public int nextIndex() {
    return delegate().nextIndex();
  }

  @CanIgnoreReturnValue
  @Override

  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() {