config.yml

services:
    my.twig.helperextension:
        class: My\OwnBundle\Twig\Extension\MyHelperExtension
        tags:
            - { name: twig.extension, alias: myhelperextension }
    my.notificationsextension:
        class: My\OwnBundle\Twig\Extension\NotificationsExtension
        arguments:
            container: "@service_container"
            context: "@security.context"
        tags:
            - { name: twig.extension, alias: mynotify }