static void testApproaches(PairManager pman1, PairManager pman2) {
        ExecutorService exec = Executors.newCachedThreadPool();
        PairManipulator
                pm1 = new PairManipulator(pman1),
                pm2 = new PairManipulator(pman2);
        PairChecker
                pcheck1 = new PairChecker(pman1),
                pcheck2 = new PairChecker(pman2);
        exec.execute(pm1);
        exec.execute(pm2);
        exec.execute(pcheck1);
        exec.execute(pcheck2);
        try {
            TimeUnit.MILLISECONDS.sleep(500);
        } catch (InterruptedException e) {
            System.out.println("Sleep interrupted");
        }
        System.out.println("pm1: " + pm1 + "\npm2: " + pm2);
        System.exit(0);
    }