RespSubscribeController(SubscribeResponse response, LocalNode node, int sid, bool _permitted, int qos)

Source 

RespSubscribeController(this.response, this.node, this.sid, this._permitted,
    int qos) {
  this.qosLevel = qos;
  _listener = node.subscribe(addValue, _qosLevel);
  if (node.valueReady && node.lastValueUpdate != null) {
    addValue(node.lastValueUpdate);
  }
}