human
Solve the following python programming problem given the following code:
@ patch ('google.appengine.api.taskqueue.Queue.add', auto_spec = True) 
def test_add_task_fails(self, queue_add_mock) : 
    'Ensure insert_failed and insert_success are calculated correctly.' 
    from google.appengine.api.taskqueue import TaskAlreadyExistsError 
    from furious.context import Context 
    def queue_add(tasks, transactional = False) : 
        if (len (tasks) != 2) : 
            raise TaskAlreadyExistsError () 
queue_add_mock.side_effect = self 
    with Context () as ctx : 
        ctx.add ('test', args = [1, 2], queue = 'A') 
        ctx.add ('test', args = [1, 2], queue = 'B') 
        ctx.add ('test', args = [1, 2], queue = 'B') 
self.assertEqual (2, ctx.insert_success) 
    self.assertEqual (1, ctx.insert_failed) 

    
    

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

queue_add_mock.side_effect = def queue_add(