public static <T> List<List<T>> lsort(List<List<T>> list) {
        list.sort((xs1, xs2) -> xs1.size() - xs2.size());
        return list;
    }
(**) Sorting a list of lists according to length of sublists
java8/src/main/java/com/shekhargulati/ninetynine_problems/_01_lists/P28.java