SessionBagInterface

class \Drupal\Core\Session\MetadataBag extends \Symfony\Component\HttpFoundation\Session\Storage\MetadataBag
class \Symfony\Component\HttpFoundation\Session\Attribute\AttributeBag implements \Symfony\Component\HttpFoundation\Session\Attribute\AttributeBagInterface, \Symfony\Component\HttpFoundation\Session\Attribute\IteratorAggregate, \Symfony\Component\HttpFoundation\Session\Attribute\Countable
class \Symfony\Component\HttpFoundation\Session\Flash\AutoExpireFlashBag implements \Symfony\Component\HttpFoundation\Session\Flash\FlashBagInterface
class \Symfony\Component\HttpFoundation\Session\Flash\FlashBag implements \Symfony\Component\HttpFoundation\Session\Flash\FlashBagInterface
class \Symfony\Component\HttpFoundation\Session\SessionBagProxy implements \Symfony\Component\HttpFoundation\Session\SessionBagInterface
class \Symfony\Component\HttpFoundation\Session\Storage\MetadataBag implements \Symfony\Component\HttpFoundation\Session\SessionBagInterface