human
Solve the following python programming problem given the following code:
def __call__(self, environ, start_response) : 
    start_time = time.time () 
    def logging_start_response(status, response_headers, * args) : 
        out = start_response (status, response_headers, * args) 
        server_time = (time.time () - start_time) 
        self._log (status, server_time, environ) 
        return out 
return self._app (environ, <MASK>) 
    
    Given the code above, what is a proper replacement for <MASK>?
assistant
#Here is a proper replacement for <MASK>.
def logging_start_response(