warmUp(cache, 0, 100);

      Set<Object> keys = cache.asMap().keySet();
      keys.clear();
      checkEmpty(keys);
      checkEmpty(cache);
    }
  }

  public void testKeySet_empty_remove() {
    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Object> keys = cache.asMap().keySet();
      assertFalse(keys.remove(null));
      assertFalse(keys.remove(6));