monitor.leave();
    }
  }

  /**
   * Returns an iterator over the elements in this queue. The iterator does not return the elements
   * in any particular order. The returned {@code Iterator} is a "weakly consistent" iterator that
   * will never throw {@link ConcurrentModificationException}, and guarantees to traverse elements
   * as they existed upon construction of the iterator, and may (but is not guaranteed to) reflect

@ElementTypesAreNonnullByDefault
public abstract class FinalizableWeakReference<T> extends WeakReference<T>
    implements FinalizableReference {
  /**
   * Constructs a new finalizable weak reference.
   *
   * @param referent to weakly reference
   * @param queue that should finalize the referent
   */
  protected FinalizableWeakReference(@CheckForNull T referent, FinalizableReferenceQueue queue) {
    super(referent, queue.queue);
    queue.cleanUp();

 *       </ul>
 * </ul>
 *
 * <p>As such, the CycleDetectingLockFactory may not be suitable for performance-critical
 * applications which involve tightly-looped or deeply-nested locking algorithms.
 *
 * @author Darick Tong
 * @since 13.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public class CycleDetectingLockFactory {

  /**

  /**
   * Returns a view of the entries stored in this cache as a thread-safe map. Modifications made to
   * the map directly affect the cache.
   *
   * <p>Iterators from the returned map are at least <i>weakly consistent</i>: they are safe for
   * concurrent use, but if the cache is modified (including by eviction) after the iterator is
   * created, it is undefined which of the changes (if any) will be reflected in that iterator.

  `Two days wrong!' sighed the Hatter.  `I told you butter
wouldn't suit the works!' he added looking angrily at the March
Hare.

  `It was the BEST butter,' the March Hare meekly replied.

  `Yes, but some crumbs must have got in as well,' the Hatter
grumbled:  `you shouldn't have put it in with the bread-knife.'

  The March Hare took the watch and looked at it gloomily:  then

      assertBasicInvariants(striped);
    }
  }

  private static void assertBasicInvariants(Striped<?> striped) {
    Set<Object> observed = Sets.newIdentityHashSet(); // for the sake of weakly referenced locks.
    // this gets the stripes with #getAt(index)
    for (int i = 0; i < striped.size(); i++) {
      Object object = striped.getAt(i);
      assertNotNull(object);

      assertBasicInvariants(striped);
    }
  }

  private static void assertBasicInvariants(Striped<?> striped) {
    Set<Object> observed = Sets.newIdentityHashSet(); // for the sake of weakly referenced locks.
    // this gets the stripes with #getAt(index)
    for (int i = 0; i < striped.size(); i++) {
      Object object = striped.getAt(i);
      assertNotNull(object);

   */
  public static Striped<Lock> lock(int stripes) {
    return custom(stripes, PaddedLock::new);
  }

  /**
   * Creates a {@code Striped<Lock>} with lazily initialized, weakly referenced locks. Every lock is
   * reentrant.
   *
   * @param stripes the minimum number of stripes (locks) required
   * @return a new {@code Striped<Lock>}
   */

  /**
   * Returns a view of the entries stored in this cache as a thread-safe map. Modifications made to
   * the map directly affect the cache.
   *
   * <p>Iterators from the returned map are at least <i>weakly consistent</i>: they are safe for
   * concurrent use, but if the cache is modified (including by eviction) after the iterator is
   * created, it is undefined which of the changes (if any) will be reflected in that iterator.
   *

@ElementTypesAreNonnullByDefault
public abstract class FinalizableWeakReference<T> extends WeakReference<T>
    implements FinalizableReference {
  /**
   * Constructs a new finalizable weak reference.
   *
   * @param referent to weakly reference
   * @param queue that should finalize the referent
   */
  protected FinalizableWeakReference(@CheckForNull T referent, FinalizableReferenceQueue queue) {
    super(referent, queue.queue);
    queue.cleanUp();