}

    static TestCondition create() {
      Lock lock = new ReentrantLock();
      Condition condition = lock.newCondition();
      return new TestCondition(lock, condition);
    }

    @Override
    public void await() throws InterruptedException {
      lock.lock();
      try {
        condition.await();
      } finally {
        lock.unlock();
      }
    }

    @Override

     * always under a lock.
     */
    private static final class SupplantableFuture implements Cancellable {
      private final ReentrantLock lock;

      @GuardedBy("lock")
      private Future<@Nullable Void> currentFuture;

      SupplantableFuture(ReentrantLock lock, Future<@Nullable Void> currentFuture) {
        this.lock = lock;
        this.currentFuture = currentFuture;
      }

        }
      };

  private static final Supplier<Lock> LOCK_SUPPLER =
      new Supplier<Lock>() {
        @Override
        public Lock get() {
          return new ReentrantLock();
        }
      };

  private static final Supplier<Lock> FAIR_LOCK_SUPPLER =
      new Supplier<Lock>() {
        @Override
        public Lock get() {
          return new ReentrantLock(true);
        }
      };

    }

    static TestCondition create() {
      Lock lock = new ReentrantLock();
      Condition condition = lock.newCondition();
      return new TestCondition(lock, condition);
    }

    @Override
    public void await() throws InterruptedException {
      lock.lock();
      try {
        condition.await();
      } finally {
        lock.unlock();
      }
    }

    @Override

	c.mu.Lock()
	bucketIdx := c.nextCleanupBucket
	timeToExpire := time.Until(c.buckets[bucketIdx].newestEntry)
	// wait for newest entry to expire before cleanup without holding lock
	if timeToExpire > 0 {
		c.mu.Unlock()
		time.Sleep(timeToExpire)
		c.mu.Lock()
	}
	for _, ent := range c.buckets[bucketIdx].entries {
		c.removeElement(ent)
	}
	c.nextCleanupBucket = (c.nextCleanupBucket + 1) % numBuckets

  /** The timestamp of the last taken event, used to measure elapsed time between events. */
  private var lastTimestampNs: Long? = null

  /** Confirm that the thread does not hold a lock on `lock` during the callback. */
  fun forbidLock(lock: Any) {
    forbiddenLocks.add(lock)
  }

  /**
   * Removes recorded events up to (and including) an event is found whose class equals [eventClass]
   * and returns it.
   */

  }

  /**
   * Invokes {@code lock.}{@link Lock#tryLock(long, TimeUnit) tryLock(timeout, unit)}
   * uninterruptibly.
   *
   * @since 30.0
   */
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
  public static boolean tryLockUninterruptibly(Lock lock, long timeout, TimeUnit unit) {

@GwtCompatible
@NullMarked
public class TearDownStack implements TearDownAccepter {
  private static final Logger logger = Logger.getLogger(TearDownStack.class.getName());

  @VisibleForTesting final Object lock = new Object();

  @GuardedBy("lock")
  final Deque<TearDown> stack = new ArrayDeque<>();

  private final boolean suppressThrows;

  public TearDownStack() {
    this.suppressThrows = false;
  }

@GwtCompatible
@NullMarked
public class TearDownStack implements TearDownAccepter {
  private static final Logger logger = Logger.getLogger(TearDownStack.class.getName());

  @VisibleForTesting final Object lock = new Object();

  @GuardedBy("lock")
  final Deque<TearDown> stack = new ArrayDeque<>();

  private final boolean suppressThrows;

  public TearDownStack() {
    this.suppressThrows = false;
  }

      in.defaultReadObject();
      lock = new Object();
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  @VisibleForTesting
  static class NonSerializableMemoizingSupplier<T extends @Nullable Object> implements Supplier<T> {
    private final Object lock = new Object();