assertFalse(CacheBuilder.newBuilder().build().asMap().values() instanceof Set);
  }

  @GwtIncompatible // CacheTesting
  public void testNullCache() {
    CountingRemovalListener<Object, Object> listener = countingRemovalListener();
    LoadingCache<Object, Object> nullCache =
        CacheBuilder.newBuilder().maximumSize(0).removalListener(listener).build(identityLoader());
    assertEquals(0, nullCache.size());