setSubTopic abstract method
@brief Method is used to set MQTT sub-topic for publishing position data.
The final topic will be "navigine/mobile/positions/" + subTopic + "/" + deviceId.
@param subTopic MQTT sub-topic for publishing position data. Must match pattern 0-9a-zA-Z_-+ and cannot be empty.
Dart code snippet: @snippet mqtt_session_example.dart dart_MqttSession_setSubTopic
Implementation
void setSubTopic(String subTopic);