toTopicWithQos method
Adds a new subscription topic with the specified Qos levelMqttQos.
Implementation
MqttSubscribeMessage toTopicWithQos(String? topic, MqttQos? withQos) {
final subTopic = MqttSubscriptionTopic(topic);
final option = MqttSubscriptionOption();
option.maximumQos = withQos;
_payload!.addSubscription(subTopic, option);
return this;
}