def stop(self, subname='total'):
        '''Stop the timer and send the total since `start()` was run

        :keyword subname: The subname to report the data to (appended to the
            client name)
        :type subname: str
        '''
        assert self._stop is None, (
            'Unable to stop, the timer is already stopped')
        self._stop = time.time()
        return self.send(subname, self._stop - self._start)