public function load(ObjectManager $manager)
 {
     for ($i = 0; $i < 5; $i++) {
         $album = new Album();
         $album->setName('Album ' . $i);
         $manager->persist($album);
         $max = $i === 0 ? 5 : 21;
         for ($n = 0; $n < $max; $n++) {
             $image = new Image();
             $image->setAlbum($album);
             $manager->persist($image);
         }
     }
     $manager->flush();
 }