docs: private static <K, V> SortedMap<K, V> filterFiltered(
        FilteredEntrySortedMap<K, V> map, Predicate<? super Entry<K, V>> entryPredicate) {
      Predicate<Entry<K, V>> predicate = Predicates.<Entry<K, V>>and(map.predicate, entryPredicate);
      return new FilteredEntrySortedMap<K, V>(map.sortedMap(), predicate);
    }