async def stop(self):
    if self.listen_server:
        self.listen_server.close()
    util.unregister_callback(self.on_proxy_changed)
    (await self.taskgroup.cancel_remaining())
async def stop(self):
    if self.listen_server:
        self.listen_server.close()
    util.unregister_callback(self.on_proxy_changed)
    (await self.taskgroup.cancel_remaining())