human
Solve the following python programming problem given the following code:
@ gen_test 
def test_aggregation_cursor_to_list_callback(self) : 
    if (not (yield at_least (self.cx, (2, 5, 1)))) : 
        raise SkipTest ('Aggregation cursor requires MongoDB >= 2.5.1') 
db = self.db 
    for collection_size in (10, 1000) : 
        expected_sum = (yield self._make_test_data (collection_size)) 
        cursor = db.test.aggregate (self.pipeline) 
        future = Future () 
        def cb(result, error) : 
            if error : 
                future.set_exception (error) 
else : 
                future.set_result (result) 
cursor.to_list (cursor, callback = cb) 
        docs = (yield future) 
        self.assertAllDocs (expected_sum, docs) 

    
    

    Fix the buggy line: cursor.to_list (cursor, callback = cb)
assistant
#Here is Python program to fix the buggy line: cursor.

cursor.to_list (collection_size, callback = cb)