PHP Fatal error: Class 'Application\Sonata\MediaBundle\ApplicationSonataMediaBundle' not found in /var/www/znata.com/app/AppKernel.php on line 47

i followed this doc to install SonataMediaBundle but i got this error:

PHP Fatal error:  Class 'Application\Sonata\MediaBundle\ApplicationSonataMediaBundle' not found in /var/www/znata.com/app/AppKernel.php on line 47

After using the sonata command t generate the app:

php app/console sonata:easy-extends:generate SonataMediaBundle

new directory was generated under:

apps/Application/Sonata/MediaBundle

everything was done but when i registred the generated application in my AppKernel.php i got that error.

public function registerbundles()
{
    return array(
        ...
        new Application\Sonata\MediaBundle\ApplicationSonataMediaBundle(),
        ...
    );
}

Have you any idea how to fix this issue ?