public function load(ObjectManager $manager)
 {
     $php = new Language();
     $php->setName('PHP');
     $php->setSlug('php');
     $javascript = new Language();
     $javascript->setName('JavaScript');
     $javascript->setSlug('javascript');
     $manager->persist($php);
     $manager->persist($javascript);
     $manager->flush();
     $this->addReference('php', $php);
     $this->addReference('javascript', $javascript);
 }