public List<AnswerInstance> getAllAnswerInstances() {
   return answerInstanceDao.getAllAnswerInstances();
 }
 public void deleteAnswerInstance(AnswerInstance answerInstance) {
   answerInstanceDao.deleteAnswerInstance(answerInstance);
 }
 public void createAnswerInstance(AnswerInstance answerInstance) {
   answerInstanceDao.createAnswerInstance(answerInstance);
 }
 public void updateAnswerInstance(AnswerInstance answerInstance) {
   answerInstanceDao.updateAnswerInstance(answerInstance);
 }
 public AnswerInstance getAnswerInstanceById(long id) {
   return answerInstanceDao.getAnswerInstanceById(id);
 }