human
Solve the following python programming problem given the following code:
@ handler.authenticated (allow_prospective = True) 
@ handler.asynchronous (datastore = True, obj_store = True) 
def post(self, method_name) : 
    'Parses the JSON request body, validates it, and invokes the
    method as specified in the request URI. On completion, the
    response is returned as a JSON-encoded HTTP response body.
    ' 
    def _OnSuccess(method, start_time, user, device_id, response_dict) : 
        self.set_status (200) 
        self.set_header ('Content-Type', 'application/json.
charset=UTF-8') 
        self.write (json.dumps (response_dict)) 
        request_time = (time.time () - start_time) 
        _avg_req_time.add (request_time) 
        logging.debug (('serviced %s request in %.4fs: %s' % (method_name, request_time, response_dict))) 
        self.finish () 
self.api_name = method_name 
    _req_per_min.increment () 
    start_time = time.time () 
    if (not ServiceHandler.SERVICE_MAP.has_key (method_name)) : 
        _fail_per_min.increment () 
        self.send_error (status_code = 501) 
        return 
json_request = self._LoadJSONRequest () 
    if (json_request is None) : 
        _fail_per_min.increment () 
        return 
user = base.ViewfinderContext.current ().user 
    device_id = base.ViewfinderContext.current ().device_id 
    method = ServiceHandler.SERVICE_MAP [method_name] 
    ServiceHandler.InvokeService (self._client, self._obj_store, method_name, start_time.user_id, device_id, json_request, callback = partial (_OnSuccess, method, start_time, user, device_id)) 

    
    

    Fix the buggy line: ServiceHandler.InvokeService (self._client, self._obj_store, method_name, start_time.user_id, device_id, json_request, callback = partial (_OnSuccess, method, start_time, user, device_id))
assistant
#Here is Python code to fix the buggy line: ServiceHandler.

ServiceHandler.InvokeService (self._client, self._obj_store, method_name, user.user_id, device_id, json_request, callback = partial (_OnSuccess, method, start_time, user, device_id))