Sulu\Bundle\MediaBundle\Entity\FileVersion::setChanged PHP Méthode

    public function setChanged($changed)
    {
        $this->changed = $changed;
        return $this;
    }

 public function initLogo()
 {
     $collectionType = new CollectionType();
     $collectionType->setName('My collection type');
     $this->em->persist($collectionType);
     $collection = new Collection();
     $collection->setType($collectionType);
     $this->em->persist($collection);
     $imageType = new MediaType();
     $imageType->setName('image');
     $imageType->setDescription('This is an image');
     $this->em->persist($imageType);
     $file = new File();
     $file->setVersion(1);
     $fileVersion = new FileVersion();
     $fileVersion->setVersion(1);
     $fileVersion->setName('logo.jpeg');
     $fileVersion->setMimeType('image/jpg');
     $fileVersion->setFile($file);
     $fileVersion->setSize(1124214);
     $fileVersion->setDownloadCounter(2);
     $fileVersion->setChanged(new \DateTime('1937-04-20'));
     $fileVersion->setCreated(new \DateTime('1937-04-20'));
     $file->addFileVersion($fileVersion);
     $this->em->persist($fileVersion);
     $this->logo = new Media();
     $this->logo->setType($imageType);
     $this->logo->setCollection($collection);
     $this->logo->addFile($file);
     $file->setMedia($this->logo);
     $this->em->persist($this->logo);
     $this->em->persist($file);
 }