in rcomp-mqtt/src/main/java/org/apache/karaf/rcomp/mqtt/MqttSource.java [56:64]
public void request(long n) {
try {
if (subScribed.compareAndSet(false, true)) {
client.subscribe(topic, this);
}
} catch (MqttException e) {
subscriber.onError(e);
}
}