public static void addObservers(Game.Builder b) {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        while (true) {

            printObservers(); ///

            int opt = getUserOption(br, 1, 4); ///
            switch (opt) {
                case 1:
                    b.addObserver(new WinnerObserver());
                    break;
                case 2:
                    b.addObserver(new AcumulatedObserver());
                    break;
                case 3:
                    b.addObserver(new IndividualRollObserver());
                    break;
                case 4:
                    return;
            }
        }
    }