class GuavaUtils {

    public static <K, V> ImmutableListMultimap<K, V> toMultimap(Map<K, List<V>> rights) {
        return rights.entrySet()
            .stream()
            .flatMap(e -> e.getValue().stream().map(right -> Pair.of(e.getKey(), right)))
            .collect(Guavate.toImmutableListMultimap(Pair::getKey, Pair::getValue));
    }

}