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.

def on_finish(self):
        """
        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.

        """
        super().on_finish()
        self.record_timing(self.request.request_time(),
                           self.__class__.__name__, self.request.method,
                           self.get_status())