public function load(ObjectManager $manager)
 {
     $data = $this->container->get('ilioscore.dataloader.learningMaterial')->getAll();
     foreach ($data as $arr) {
         switch ($arr['type']) {
             case 'citation':
                 $entity = new CitationLearningMaterial();
                 break;
             case 'link':
                 $entity = new LinkLearningMaterial();
                 break;
             case 'file':
                 $entity = new FileLearningMaterial();
                 $entity->setCopyrightPermission($arr['copyrightPermission']);
                 $entity->setCopyrightRationale($arr['copyrightRationale']);
                 break;
         }
         $entity->setId($arr['id']);
         $entity->setTitle($arr['title']);
         $entity->setDescription($arr['description']);
         $entity->setOriginalAuthor($arr['originalAuthor']);
         $entity->setToken($arr['token']);
         $entity->setUserRole($this->getReference('learningMaterialUserRoles' . $arr['userRole']));
         $entity->setStatus($this->getReference('learningMaterialStatus' . $arr['status']));
         $entity->setOwningUser($this->getReference('users' . $arr['owningUser']));
         $manager->persist($entity);
         $this->addReference('learningMaterials' . $arr['id'], $entity);
     }
     $manager->flush();
 }