def send_time(self, key=None):
        """
        Send current time from start time.
        """
        time_delta = self.get_time_delta()

        if key:
            check_key(key)
            self._metrics.time(key, time_delta.total_seconds())
        else:
            self._metrics.time(self.key, time_delta.total_seconds())

        Send current time from start time.
        
st2common/st2common/metrics/base.py