Validate the answer with our Validator(s)

            This will support one or more validator classes being applied to
            this question.  If there are multiple, all validators must return
            True for the answer to be valid.

def validate(self, answer):
        """ Validate the answer with our Validator(s)

            This will support one or more validator classes being applied to
            this question.  If there are multiple, all validators must return
            True for the answer to be valid.
        """
        if answer is None:
            return False
        else:
            if isinstance(self.validator, list):
                for v in self.validator:
                    if not v.validate(answer):
                        return False
                return True
            else:
                return self.validator.validate(answer)