human
Solve the following python programming problem given the following code:
@ defer.inlineCallbacks 
def test_sleep(self) : 
    @ defer.inlineCallbacks 
    def competing_callback() : 
        with LoggingContext () as competing_context : 
            competing_context.test_key = 'competing' 
            (yield sleep (0)) 
            self._check_test_key ('competing') 
reactor.callLater (0, <MASK>) 
    with LoggingContext () as context_one : 
        context_one.test_key = 'one' 
        (yield sleep (0)) 
        self._check_test_key ('one') 
    
    Given the code above, what is a proper replacement for <MASK>?
assistant
#Here is a proper replacement for <MASK>.
def competing_callback(