sonatabundle installation ApplicationSonataMediaBundle not found

Question

I tried to follow the tutorial installation for SonataBundle tutorial

I change only mapping in this way

doctrine:
    dbal:
        driver: pdo_mysql
        host: '%database_host%'
        port: '%database_port%'
        dbname: '%database_name%'
        user: '%database_user%'
        password: '%database_password%'
        charset: UTF8
        # if using pdo_sqlite as your database driver:
        #   1. add the path in parameters.yml
        #     e.g. database_path: '%kernel.project_dir%/var/data/data.sqlite'
        #   2. Uncomment database_path in parameters.yml.dist
        #   3. Uncomment next line:
        #path: '%database_path%'
        types:
            json: Sonata\Doctrine\Types\JsonType
    orm:
        auto_generate_proxy_classes: "%kernel.debug%"
        naming_strategy: doctrine.orm.naming_strategy.underscore
        auto_mapping: true
        mappings:
                    ApplicationSonataMediaBundle: ~
                    SonataMediaBundle: ~

the command

php app/console sonata:easy-extends:generate --dest=src SonataMediaBundle

generate in src/Application/Sonata/MediaBundle/ApplicationSonataMediaBundle

but always I get this error :

Class 'Application\Sonata\MediaBundle\ApplicationSonataMediaBundle' not found