stop method
Stops the node: sends a goodbye, closes the connection, and ends the loop.
Implementation
Future<void> stop() async {
if (_stopped) return;
_stopped = true;
final typed = _typed;
if (typed != null && typed.isOpen) {
typed.send(const NodeGoodbye('shutdown'));
await typed.close();
}
await _loop;
_loop = null;
if (!_states.isClosed) await _states.close();
}