public Question randomQuestion() {
        int rndQuestion = random.nextInt(QUESTION_COUNT);
        int rndExc = random.nextInt(excDatas.length);
        ExcData excData = excDatas[rndExc];

        switch (rndQuestion) {
            case 0:
                return new ByDescription(excData);
            case 1:
                return new IsChecked(excData);
            case 2:
                return new ParentClass(excData);
            case 3:
                return new WhichPackage(excData);
            default:
                throw new IllegalStateException("Question class not exists with index " + rndQuestion);
        }
    }