return ticker;
    }
    return recordsTime ? Ticker.systemTicker() : NULL_TICKER;
  }

  /**
   * Specifies a listener instance that caches should notify each time an entry is removed for any
   * {@linkplain RemovalCause reason}. Each cache created by this builder will invoke this listener
   * as part of the routine maintenance described in the class documentation above.
   *

    } finally {
      joinPool(e);
    }
  }

  private static void assertListenerRunImmediately(ListenableFuture<?> future) {
    CountingRunnable listener = new CountingRunnable();
    future.addListener(listener, directExecutor());
    assertEquals(1, listener.count);
  }

  private static final class CountingRunnable implements Runnable {
    int count;

    @Override
    public void run() {

      return sync.wasInterrupted();
    }

    /**
     * {@inheritDoc}
     *
     * @since 10.0
     */
    @Override
    public void addListener(Runnable listener, Executor exec) {
      executionList.add(listener, exec);
    }

    /**
     * Subclasses should invoke this method to set the result of the computation to {@code value}.

      return sync.wasInterrupted();
    }

    /**
     * {@inheritDoc}
     *
     * @since 10.0
     */
    @Override
    public void addListener(Runnable listener, Executor exec) {
      executionList.add(listener, exec);
    }

    /**
     * Subclasses should invoke this method to set the result of the computation to {@code value}.

        new Thread(() -> latch.countDown()).start();
      }

      future.addListener(listenerLatch::countDown, exec);
    }

    assertSame(Boolean.TRUE, future.get());
    // Wait for the listener latch to complete.
    listenerLatch.await(500, MILLISECONDS);

    exec.shutdown();
    exec.awaitTermination(500, MILLISECONDS);
  }

    final Error error = new Error();
    final CountDownLatch latch = new CountDownLatch(1);
    TestService service = new TestService();
    service.addListener(
        new Service.Listener() {
          @Override
          public void running() {
            throw error;
          }

          @Override
          public void failed(State from, Throwable failure) {

the bank, with her head in the lap of her sister, who was gently
brushing away some dead leaves that had fluttered down from the
trees upon her face.

  `Wake up, Alice dear!' said her sister; `Why, what a long
sleep you've had!'

  `Oh, I've had such a curious dream!' said Alice, and she told
her sister, as well as she could remember them, all these strange

  final long refreshNanos;

  /** Entries waiting to be consumed by the removal listener. */
  // TODO(fry): define a new type which creates event objects and automates the clear logic
  final Queue<RemovalNotification<K, V>> removalNotificationQueue;

  /**
   * A listener that is invoked when an entry is removed due to expiration or garbage collection of
   * soft/weak entries.
   */

  QueuingRemovalListener<Object, Object> listener;

  @Override
  protected void setUp() {
    listener = queuingRemovalListener();
  }

  public void testGet() {
    Object computed = new Object();
    LoadingCache<Object, Object> cache =
        CacheBuilder.newBuilder()
            .maximumSize(0)
            .removalListener(listener)
            .build(constantLoader(computed));

    void call(L listener);
  }

  /**
   * Adds a listener that will be called using the given executor when events are later {@link
   * #enqueue enqueued} and {@link #dispatch dispatched}.
   */
  public void addListener(L listener, Executor executor) {
    checkNotNull(listener, "listener");
    checkNotNull(executor, "executor");
    listeners.add(new PerListenerQueue<>(listener, executor));
  }

  /**