Sulu\Bundle\MediaBundle\Entity\CollectionInterface::getId PHP Method

    public function getId();

 /**
  * {@inheritdoc}
  */
 public function findCollectionSet($depth = 0, $filter = [], CollectionInterface $collection = null, $sortBy = [], UserInterface $user = null, $permission = null)
 {
     try {
         $queryBuilder = $this->createQueryBuilder('collection')->addSelect('collectionMeta')->addSelect('defaultMeta')->addSelect('collectionType')->addSelect('collectionParent')->addSelect('parentMeta')->addSelect('collectionChildren')->leftJoin('collection.meta', 'collectionMeta')->leftJoin('collection.defaultMeta', 'defaultMeta')->leftJoin('collection.type', 'collectionType')->leftJoin('collection.parent', 'collectionParent')->leftJoin('collection.children', 'collectionChildren')->leftJoin('collectionParent.meta', 'parentMeta')->where('collection.depth <= :depth1 OR collectionChildren.depth <= :depth2');
         if ($collection !== null) {
             $queryBuilder->andWhere('collection.lft BETWEEN :lft AND :rgt AND collection.id != :id');
         }
         if (array_key_exists('search', $filter) && $filter['search'] !== null) {
             $queryBuilder->andWhere('collectionMeta.title LIKE :search');
         }
         if (array_key_exists('locale', $filter)) {
             $queryBuilder->andWhere('collectionMeta.locale = :locale OR defaultMeta.locale != :locale');
         }
         if ($sortBy !== null && is_array($sortBy) && count($sortBy) > 0) {
             foreach ($sortBy as $column => $order) {
                 $queryBuilder->addOrderBy('collectionMeta.' . $column, strtolower($order) === 'asc' ? 'ASC' : 'DESC');
             }
         }
         if ($user !== null && $permission != null) {
             $this->addAccessControl($queryBuilder, $user, $permission, Collection::class, 'collection');
         }
         $collectionDepth = $collection !== null ? $collection->getDepth() : 0;
         $query = $queryBuilder->getQuery();
         $query->setParameter('depth1', $collectionDepth + $depth);
         $query->setParameter('depth2', $depth + 1);
         if ($collection !== null) {
             $query->setParameter('lft', $collection->getLft());
             $query->setParameter('rgt', $collection->getRgt());
             $query->setParameter('id', $collection->getId());
         }
         if (array_key_exists('search', $filter) && $filter['search'] !== null) {
             $query->setParameter('search', '%' . $filter['search'] . '%');
         }
         if (array_key_exists('limit', $filter)) {
             $query->setMaxResults($filter['limit']);
         }
         if (array_key_exists('offset', $filter)) {
             $query->setFirstResult($filter['offset']);
         }
         if (array_key_exists('locale', $filter)) {
             $query->setParameter('locale', $filter['locale']);
         }
         return new Paginator($query);
     } catch (NoResultException $ex) {
         return [];
     }
 }