this doesn't work. You have to do:
````php
use Symfony\Component\DependencyInjection\Definition;
use Symfony\Component\DependencyInjection\Reference;

$definition = new Definition('Example\Event\CreateMenuItemFromNodeListener', array(
    new Reference('knp_menu.menu_provider'),
));
$definition->addTag('kernel.event_listener', array(
    'event' => 'cmf_menu.create_menu_item_from_node',
    'method' => 'onCreateMenuItemFromNode',
));

$container->setDefinition('acme_demo.listener.menu_referrer_listener', $definition);
````