AppKernel.php::registerBundles()

public function registerBundles()
{
    $bundles = [
        new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
        new Symfony\Bundle\SecurityBundle\SecurityBundle(),
        new Symfony\Bundle\TwigBundle\TwigBundle(),
        new Symfony\Bundle\MonologBundle\MonologBundle(),
        new Symfony\Bundle\SwiftmailerBundle\SwiftmailerBundle(),
        new Doctrine\Bundle\DoctrineBundle\DoctrineBundle(),
        new Doctrine\Bundle\MigrationsBundle\DoctrineMigrationsBundle(),
        new Sensio\Bundle\FrameworkExtraBundle\SensioFrameworkExtraBundle(),

        // Sonata admin
        new \Sonata\CoreBundle\SonataCoreBundle(),
        new \Sonata\BlockBundle\SonataBlockBundle(),
        new \Knp\Bundle\MenuBundle\KnpMenuBundle(),
        new \Sonata\DoctrineORMAdminBundle\SonataDoctrineORMAdminBundle(),
        new \Sonata\TranslationBundle\SonataTranslationBundle(),
        new \Sonata\AdminBundle\SonataAdminBundle(),
        new \Knp\Bundle\MarkdownBundle\KnpMarkdownBundle(),
        new \Sonata\FormatterBundle\SonataFormatterBundle(),

        new AppBundle\AppBundle(),
    ];

    if (in_array($this->getEnvironment(), ['dev', 'test'], true)) {
        $bundles[] = new Symfony\Bundle\DebugBundle\DebugBundle();
        $bundles[] = new Symfony\Bundle\WebProfilerBundle\WebProfilerBundle();
        $bundles[] = new Sensio\Bundle\DistributionBundle\SensioDistributionBundle();
        $bundles[] = new Sensio\Bundle\GeneratorBundle\SensioGeneratorBundle();
    }

    return $bundles;
}