def METHOD_NAME(self):
    """Test the behaviour of review scores"""
    review = self._save_review(None)
    self.assertEqual(review.avg_score, 1.0)
    self._save_review(review, ('1', '0'))
    self.assertEqual(review.avg_score, 0.5)
    self._save_review(review, ('-1', '1'))
    self.assertEqual(review.avg_score, 0)