public function get_order_master_collections()
    {
        $baseIds = $this->getOrderMasterCollectionsBaseIds();

        $collectionReferences = $this->app['repo.collection-references']->findHavingOrderMaster($baseIds);
        $groups = new CollectionReferenceCollection($collectionReferences);

        $collections = [];

        foreach ($groups->groupByDataboxIdAndCollectionId() as $databoxId => $group) {
            foreach ($group as $collectionId => $index) {
                $collections[$index] = \collection::getByCollectionId($this->app, $databoxId, $collectionId);
            }
        }

        ksort($collections);

        return $collections;
    }