docs: public static <K, V> ImmutableListMultimap<K, V> loadMultimap(final CharSource source,
        final Function<String, K> keyFunction, final Function<String, V> valueFunction)
        throws IOException {
      final ImmutableListMultimap.Builder<K, V> ret = ImmutableListMultimap.builder();
      loadMapToSink(source, MapUtils.asMapSink(ret), keyFunction, valueFunction,
          IsCommentLine.INSTANCE);
      return ret.build();
    }