import asyncio


class SleepTest:
    @staticmethod
    async def __sleep_test():
        while True:
            await asyncio.sleep(0)

    def main(self):
        try:
            print(f'{self.__class__.__name__} up')
            asyncio.run(self.__sleep_test())
        except KeyboardInterrupt:
            print(f'{self.__class__.__name__} down')


if __name__ == '__main__':
    SleepTest().main()