OEModule\PatientTicketing\models\Queue::getQueueSet PHP Method

    public function getQueueSet()
    {
        $root = $this->getRootQueue();
        if (is_array($root)) {
            throw new \Exception('Unexpected configuration of multiple root queues' . print_r($root, true));
            $rid = $root[0]->id;
        } else {
            $rid = $root->id;
        }
        return QueueSet::model()->findByAttributes(array('initial_queue_id' => $rid));
    }