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

 * test with reference to the same "lock-like object", and then their interactions with that object
 * are choreographed via the various methods on this class.
 *
 * <p>A "lock-like object" is really any object that may be used for concurrency control. If the
 * {@link #callAndAssertBlocks} method is ever called in a test, the lock-like object must have a

 * test with reference to the same "lock-like object", and then their interactions with that object
 * are choreographed via the various methods on this class.
 *
 * <p>A "lock-like object" is really any object that may be used for concurrency control. If the
 * {@link #callAndAssertBlocks} method is ever called in a test, the lock-like object must have a

						<div class="input-group-append">
							<span class="input-group-text">
								<i class="fa fa-lock fa-fw" aria-hidden="true"></i>
							</span>
						</div>
					</div>
					<div class="text-center">
						<button type="submit" name="changePassword"
							class="btn btn-primary btn-block"
							value="<la:message key="labels.login.update"/>">
							<i class="fa fa-pencil-alt" aria-hidden="true"></i>

  private final Object lock = new Object();

  /**
   * The runnable, executor pairs to execute. This acts as a stack threaded through the {@link
   * RunnableExecutorPair#next} field.
   */
  @GuardedBy("lock")
  private @Nullable RunnableExecutorPair runnables;

  @GuardedBy("lock")
  private boolean executed;

  /** Creates a new, empty {@link ExecutionList}. */

						<div class="input-group-append">
							<span class="input-group-text">
								<i class="fa fa-lock fa-fw" aria-hidden="true"></i>
							</span>
						</div>
					</div>
					<div class="text-center">
						<button type="submit" name="login"
							class="btn btn-primary btn-block"
							value="<la:message key="labels.login"/>">
							<i class="fa fa-sign-in" aria-hidden="true"></i>

                  : t;
          releaseShared(finalState);
        } else if (getState() == COMPLETING) {
          // If some other thread is currently completing the future, block until
          // they are done so we can guarantee completion.
          acquireShared(-1);
        }
        return doCompletion;
      }
    }

                  : t;
          releaseShared(finalState);
        } else if (getState() == COMPLETING) {
          // If some other thread is currently completing the future, block until
          // they are done so we can guarantee completion.
          acquireShared(-1);
        }
        return doCompletion;
      }
    }

   *
   * Lock lockA = factory1.newReentrantLock(MyLockOrder.FIRST);
   * Lock lockB = factory1.newReentrantLock(MyLockOrder.FIRST);
   * Lock lockC = factory2.newReentrantLock(MyLockOrder.FIRST);
   *
   * lockA.lock();
   *
   * lockB.lock(); // will throw an IllegalStateException
   * lockC.lock(); // will throw an IllegalStateException
   *
   * lockA.lock(); // reentrant acquisition is okay
   * }

    }

    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