: new CycleDetectingReentrantReadWriteLock(
              requireNonNull(lockGraphNodes.get(rank)), fair);
    }
  }

  //////// Implementation /////////

  private static final LazyLogger logger = new LazyLogger(CycleDetectingLockFactory.class);

  final Policy policy;

  private CycleDetectingLockFactory(Policy policy) {
    this.policy = checkNotNull(policy);
  }

  /**

@DoNotMock("Use ClosingFuture.from(Futures.immediate*Future)")
@J2ktIncompatible
@GwtIncompatible // TODO(dpb): GWT compatibility.
public final class ClosingFuture<V extends @Nullable Object> {

  private static final LazyLogger logger = new LazyLogger(ClosingFuture.class);

  /**
   * An object that can capture objects to be closed later, when a {@link ClosingFuture} pipeline is
   * done.
   */
  public static final class DeferredCloser {