human
Solve the following python programming problem given the following code:
@ gen_test 
def test_del_on_child_greenlet(self) : 
    if (tornado_version < (4, 0, 0, 0)) : 
        raise SkipTest ('Tornado 3') 
(client, server) = self.client_server (auto_ismaster = True) 
    self.cursor = client.test.collection.find () 
    future = self.cursor.fetch_next 
    request = (yield self.run_thread (server.receives, OpQuery)) 
    request.replies ({ 
        '_id' : 1, 
}, cursor_id = 123) 
    (yield future) 
    def f() : 
        del self.cursor 
greenlet.greenlet (f).switch () 
    (yield self.pause (0)) 
    if ('PyPy' in sys.version) : 
        gc.collect () 
(yield self.run_thread (self.receives, OpKillCursors)) 

    
    

    Fix the buggy line: (yield self.run_thread (self.receives, OpKillCursors))
assistant
#Here is Python code to find () 
.

(yield self.run_thread (server.receives, OpKillCursors))