public static int[] sleepSort(int... args) {
        final int[] sorted = new int[args.length];
        final AtomicInteger index = new AtomicInteger(0);
        List<Thread> threads = new ArrayList<Thread>(0);
        for (int i = 0; i < args.length; i++) {
            final int x = i;
            Thread sorter = new Thread(() -> {
                try {
                    Thread.sleep(args[x]);
                } catch (InterruptedException ex) { 
                    // shrug
                }
                sorted[index.getAndIncrement()] = args[x];
            });
            sorter.setDaemon(true);
            sorter.start();
            threads.add(sorter);
        }
        try {
            for (Thread t : threads) { t.join(); }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return sorted;
    }