def _get_response_ms(self):
        """
        Get the duration of the request response cycle is milliseconds.
        In case of negative duration 0 is returned.
        """
        response_timedelta = now() - self.log['requested_at']
        response_ms = int(response_timedelta.total_seconds() * 1000)
        return max(response_ms, 0)
Get the duration of the request response cycle is milliseconds.
        In case of negative duration 0 is returned.