getStudentSubQuestions().set(i, newSubQuestion);
    public void setSubQuestionByItem(SubQuestion newSubQuestion) {        int i = 0;        for (; i < getStudentSubQuestions().size(); i++) {            SubQuestion subQuestion = getStudentSubQuestions().get(i);            if (getItemId() != null && subQuestion.getItemId() != null) {                if (getItemId().equals(subQuestion.getItemId())) {                    break;                }            } else if (getItemId() == null && subQuestion.getItemId() == null) {                break;            }        }        getStudentSubQuestions().set(i, newSubQuestion);    }