human
Solve the following python programming problem given the following code:
@ mock.patch ('bareon.utils.grub.os.path.isdir') 
def test_guess_grub2_conf(self, mock_isdir) : 
    side_effect_values = { 
        '/target/boot/grub' : True, 
        '/target/boot/grub2' : False, 
} 
    def side_effect(key) : 
        return side_effect_values [key] 
mock_isdir.side_effect = self 
    self.assertEqual (gu.guess_grub2_conf ('/target'), '/boot/grub/grub.cfg') 
    side_effect_values = { 
        '/target/boot/grub' : False, 
        '/target/boot/grub2' : True, 
} 
    self.assertEqual (gu.guess_grub2_conf ('/target'), '/boot/grub2/grub.cfg') 

    
    

    Fix the buggy line: mock_isdir.side_effect = self
assistant
#Here is Python code to fix the buggy line: mock_isdir.

mock_isdir.side_effect = side_effect