} else if (unfiltered instanceof FilteredMultimap) {
      FilteredMultimap<K, V> prev = (FilteredMultimap<K, V>) unfiltered;
      return filterFiltered(prev, Maps.keyPredicateOnEntries(keyPredicate));
    } else {
      return new FilteredKeyMultimap<>(unfiltered, keyPredicate);
    }
  }

  /**