human
Solve the following python programming problem given the following code:
@ mock.patch.object (fakelibvirt.virConnect, 'registerCloseCallback') 
def test_close_callback(self, mock_close) : 
    self.close_callback = None 
    def set_close_callback(cb, opaque) : 
        self.close_callback = cb 
mock_close.side_effect = self 
    self.host.get_connection () 
    self.assertTrue (self.close_callback) 

    
    

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

mock_close.side_effect = def set_close_callback(