human
Solve the following python programming problem given the following code:
@ mock.patch ('sahara.utils.openstack.base.retrieve_auth_url') 
def test_retrieve_auth_url(self, url_for_mock) : 
    correct = 'https://127.0.0.1:8080/v2.0/' 
    def _assert(uri) : 
        url_for_mock.return_value = uri 
        self.assertEqual (correct, utils.retrieve_auth_url ()) 
_assert (('%s/' % self)) 
    _assert ('https://127.0.0.1:8080') 
    _assert ('https://127.0.0.1:8080/') 
    _assert ('https://127.0.0.1:8080/v2.0') 
    _assert ('https://127.0.0.1:8080/v2.0/') 
    _assert ('https://127.0.0.1:8080/v42/') 
    _assert ('https://127.0.0.1:8080/foo') 

    
    

    Fix the buggy line: _assert (('%s/' % self))
assistant
#Here is Python program to fix the buggy line: _assert (('%s/' % self))
.

_assert (('%s/' % correct))