Lists.java

    @SuppressWarnings("unchecked")
    @SafeVarargs
    public static <T> List<T> sortBy(List<T> list, Function<? super T, ? super Comparable>... function) {
        Comparator<T> comparator = (o1, o2) -> {
            for (int i = 0; i < function.length; i++) {
                Object obj1 = function[i].apply(o1);
                Object obj2 = function[i].apply(o2);

                int result;
                if (obj1 == null || obj2 == null) {
                    if (obj1 == null && obj2 == null) {
                        result = 0;
                    } else {
                        result = obj1 == null ? 1 : -1; //nullsLast
                    }
                } else {
                    result = ((Comparable) obj1).compareTo(obj2);
                }
                if (i == function.length - 1) {
                    return result;
                }
                if (result != 0) {
                    return result;
                }
            }
            return 0;
        };
        Collections.sort(list, comparator);
        return list;
    }