code: def validate(self):
          
          try:
              assert self.question_type == exercises.MULTIPLE_SELECTION, "Assumption Failed: Question should be multiple selection type"
              assert len(self.answers) > 0, "Assumption Failed: Multiple selection question should have answers"
              for a in self.answers:
                  assert 'answer' in a and isinstance(a['answer'], str), "Assumption Failed: Answer in answer list is not a string"
                  assert 'correct' in a and isinstance(a['correct'], bool), "Assumption Failed: Correct indicator is not a boolean in answer list"
              for h in self.hints:
                  assert isinstance(h, str), "Assumption Failed: Hint in hint list is not a string"
              return super(MultipleSelectQuestion, self).validate()
          except AssertionError as ae:
              raise InvalidQuestionException("Invalid question: {0}".format(self.__dict__))
docs: validate: Makes sure multiple selection question is valid
              Args: None
              Returns: boolean indicating if multiple selection question is valid