}

  /** {@link RemovalListener} that adds all {@link RemovalNotification} objects to a queue. */
  @GwtIncompatible // ConcurrentLinkedQueue
  static class QueuingRemovalListener<K, V> extends ConcurrentLinkedQueue<RemovalNotification<K, V>>
      implements RemovalListener<K, V> {

    @Override
    public void onRemoval(RemovalNotification<K, V> notification) {
      add(notification);
    }
  }

  /**

            .maximumSize(0)
            .removalListener(listener)
            .build(constantLoader(computed));

    Object key = new Object();
    assertSame(computed, cache.getUnchecked(key));
    RemovalNotification<Object, Object> notification = listener.remove();
    assertSame(key, notification.getKey());
    assertSame(computed, notification.getValue());
    assertSame(RemovalCause.SIZE, notification.getCause());

            .maximumSize(0)
            .removalListener(listener)
            .build(constantLoader(computed));

    Object key = new Object();
    assertSame(computed, cache.getUnchecked(key));
    RemovalNotification<Object, Object> notification = listener.remove();
    assertSame(key, notification.getKey());
    assertSame(computed, notification.getValue());
    assertSame(RemovalCause.SIZE, notification.getCause());

    // contain the computed value (b -> b), since the clear() happened before the computation
    // completed.
    assertEquals(1, listener.size());
    RemovalNotification<String, String> notification = listener.remove();
    assertEquals("a", notification.getKey());
    assertEquals("a", notification.getValue());
    assertEquals(1, cache.size());

    // contain the computed value (b -> b), since the clear() happened before the computation
    // completed.
    assertEquals(1, listener.size());
    RemovalNotification<String, String> notification = listener.remove();
    assertEquals("a", notification.getKey());
    assertEquals("a", notification.getValue());
    assertEquals(1, cache.size());

  private long currentTimeNanos() {
    return ticker.read();
  }

  private void alertListenerIfPresent(K key, V value, RemovalCause cause) {
    if (removalListener != null) {
      removalListener.onRemoval(RemovalNotification.create(key, value, cause));
    }
  }

  @SuppressWarnings("GoodTime") // timestamps as numeric primitives
  private V load(K key) throws ExecutionException {
    long startTime = ticker.read();

    RuntimeException e = new RuntimeException();
    RemovalListener<Object, Object> listener =
        new RemovalListener<Object, Object>() {
          @Override
          public void onRemoval(RemovalNotification<Object, Object> notification) {
            throw e;
          }
        };

    CacheBuilder<Object, Object> builder = createCacheBuilder().removalListener(listener);

    int[] stats = new int[4];

    RemovalListener<Integer, Integer> countingListener =
        new RemovalListener<Integer, Integer>() {
          @Override
          public void onRemoval(RemovalNotification<Integer, Integer> notification) {
            switch (notification.getCause()) {
              case EXPIRED:
                stats[0]++;
                break;
              case EXPLICIT:

    RemovalListener<Integer, AtomicInteger> removalListener =
        new RemovalListener<Integer, AtomicInteger>() {
          @Override
          public void onRemoval(RemovalNotification<Integer, AtomicInteger> notification) {
            if (notification.wasEvicted()) {
              evictionCount.incrementAndGet();
              totalSum.addAndGet(notification.getValue().get());
            }

          return new SimpleStatsCounter();
        }
      };

  enum NullListener implements RemovalListener<Object, Object> {
    INSTANCE;

    @Override
    public void onRemoval(RemovalNotification<Object, Object> notification) {}
  }

  enum OneWeigher implements Weigher<Object, Object> {
    INSTANCE;

    @Override
    public int weigh(Object key, Object value) {
      return 1;
    }