code: def on_finish(self):
          
          super().on_finish()
          self.record_timing(self.request.request_time(),
                             self.__class__.__name__, self.request.method,
                             self.get_status())
docs: Records the time taken to process the request.
  
          This method records the amount of time taken to process the request
          (as reported by
          :meth:`~tornado.httputil.HTTPServerRequest.request_time`) under the
          path defined by the class's module, it's name, the request method,
          and the status code.  The :meth:`.record_timing` method is used
          to send the metric, so the configured namespace is used as well.