assertThat(cache.asMap().remove(key, -1)).isFalse();
        assertThat(cache.asMap().containsKey(key)).isFalse();
      }
      checkEmpty(cache);
    }
  }


  public void testKeySet_populated() {
    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Object> keys = cache.asMap().keySet();
      List<Entry<Object, Object>> warmed = warmUp(cache);