code: public static <K, T> StreamEx<T> ofValues(Map<K, T> map, Predicate<? super K> keyFilter) {
          return EntryStream.of(map).filterKeys(keyFilter).values();
      }
docs: Returns a sequential {@code StreamEx} of given {@link Map} values which
  corresponding keys match the supplied filter.
  
  @param <K> the type of map keys
  @param <T> the type of map values and created stream elements
  @param map input map
  @param keyFilter a predicate used to test keys
  @return a sequential {@code StreamEx} over the values of given
  {@code Map} which corresponding keys match the supplied filter.
  @throws NullPointerException if map is null
  @see Map#values()