unsubscribe method
Implementation
@override
Future<void> unsubscribe(
String topic, {
RelayerUnsubscribeOptions? opts,
}) async {
_isInitialized();
if (opts?.id != null) {
await _unsubscribeById(topic, opts!.id!, opts: opts);
} else {
await _unsubscribeByTopic(topic, opts: opts);
}
}