human
Solve the following python programming problem given the following code:
@ mock.patch ('codalab.lib.path_util.os') 
def test_make_directory_if_exists(self, mock_os) : 
    '
    Check that make_directory still works if the directory exists.
    ' 
    mock_os.path.join = os.path.join 
    failures = [0] 
    def mkdir_when_directory_exists(path) : 
        failures [0] += 1 
        error = OSError () 
        error.errno = errno.EEXIST 
        raise error 
mock_os.mkdir.side_effect = failures 
    path_util.make_directory (self.test_path) 
    self.assertEqual (mock_os.mkdir.call_args_list, self.mkdir_calls) 
    self.assertEqual (failures [0], 1) 

    
    

    Fix the buggy line: mock_os.mkdir.side_effect = failures
assistant
#Here is Python program to fix the buggy line: mock_os.

mock_os.mkdir.side_effect = def mkdir_when_directory_exists(