'Test the backend when usernames are supplied.'

def test_with_username(self):

    invalid_data_dicts = [{'identification': 'john', 'password': 'inhalefish'}, {'identification': 'alice', 'password': 'blowfish'}]
    for invalid_dict in invalid_data_dicts:
        result = self.backend.authenticate(identification=invalid_dict['identification'], password=invalid_dict['password'])
        self.assertFalse(isinstance(result, User))
    result = self.backend.authenticate(identification='john', password='blowfish')
    self.assertTrue(isinstance(result, User))
