def METHOD_NAME(self):
    self.assertEqual(None, self.backend.authenticate(username='toto', password='totopwd'))
    query_db("INSERT INTO %s (username, password) VALUES ('toto', '%s')" % (settings.AUTHENT_TABLENAME, password2md5('totopwd')))
    # Valid returns a user
    self.assertNotEqual(None, self.backend.authenticate(username='toto', password='totopwd'))
    # SQL injection safe ?
    self.assertEqual(None, self.backend.authenticate(username='toto', password="' OR '' = '"))