List<PlayerQuizInstance> determineQuizWinner(List<PlayerQuizInstance> quizPlayInstances) {
        PlayerQuizInstance maxScore = null;
        List<PlayerQuizInstance> winners = new ArrayList<PlayerQuizInstance>();
        if (quizPlayInstances.isEmpty()) {
            return winners;
        }
        maxScore = Collections.max(quizPlayInstances, new Comparator<PlayerQuizInstance>() {
            @Override
            public int compare(PlayerQuizInstance o1, PlayerQuizInstance o2) {
                if (o1.getTotalScore() > o2.getTotalScore()) {
                    return 1;
                } else if ((o1.getTotalScore() < o2.getTotalScore())) {
                    return -1;
                } else return 0;
            }
        });
        for (PlayerQuizInstance current : quizPlayInstances) {
            if (maxScore.getTotalScore() == current.getTotalScore()) {
                winners.add(current);
            }
        }

        return winners;
    }