def can_user_vote(self, user):
        """
        Test whether the passed user is allowed to vote on this
        review
        """
        if not user.is_authenticated():
            return False, _(u"Only signed in users can vote")
        vote = self.votes.model(review=self, user=user, delta=1)
        try:
            vote.full_clean()
        except __HOLE__ as e:
            return False, u"%s" % e
        return True, ""
dataset/ETHPy150Open django-oscar/django-oscar/src/oscar/apps/catalogue/reviews/abstract_models.py/AbstractProductReview.can_user_vote