    def start_session(self, session_time, total_user, spawn_speed=None):
        """
        To start a benchmark session. If it's running It will return immediately.
        Paras:
        * session_time: session time in sec
        * total_user: user count need to be spawned
        * spawn_speed: user spawning speed, in user/sec
        """
        if spawn_speed is None:
            spawn_speed = total_user
        loop = asyncio.get_event_loop()
        if not loop.is_running():
            self._stop_loop_flag = True
        loop.create_task(self._start_session(session_time, total_user, spawn_speed))
        if not loop.is_running():
            loop.run_forever()
To start a benchmark session. If it's running It will return immediately.
Paras:
* session_time: session time in sec
* total_user: user count need to be spawned
* spawn_speed: user spawning speed, in user/sec
src/bentoml/_internal/utils/benchmark.py