async def push_stats(self):
        """Push current stats to Redis."""
        snapshot = self._make_stats()
        try:
            serialized = json.dumps(snapshot)
            await self._call_redis(aioredis.Redis.set, state.MANAGER_LISTENER_STATS, serialized)
            await self._call_redis(aioredis.Redis.expire, state.MANAGER_LISTENER_STATS, 3600)
        except TypeError:
            logger.error(__(
                "Listener can't serialize statistics:\n\n{}",
                traceback.format_exc()
            ))
        except aioredis.RedisError:
            logger.error(__(
                "Listener can't store updated statistics:\n\n{}",
                traceback.format_exc()
            ))
Push current stats to Redis.