open fun subscribeAcknowledge(subscribeMessageId: Int, grantedQoSLevels: MutableList<MqttQoS>): MqttEndpoint
Sends the SUBACK message to the remote MQTT client
subscribeMessageId - identifier of the SUBSCRIBE message to acknowledge
grantedQoSLevels - granted QoS levels for the requested topics
Return
a reference to this, so the API can be used fluently