public static <K extends @Nullable Object, V extends @Nullable Object>
      Multimap<K, V> filterValues(Multimap<K, V> unfiltered, Predicate<? super V> valuePredicate) {
    return filterEntries(unfiltered, Maps.valuePredicateOnEntries(valuePredicate));
  }

  /**
   * Returns a multimap containing the mappings in {@code unfiltered} whose values satisfy a