Twig. How to add dir with templates

gistfile1.aw

<?php

use Symfony\Component\DependencyInjection\ContainerInterface;

class Foo_Twig_Extension extends Twig_Extension
{
    protected $container;

    public function __construct(ContainerInterface $container)
    {
        $this->container = $container;
    }

    public function initRuntime(Twig_Environment $environment)
    {
        $globalTemplateDir = $this->container->getParameter('kernel.root_dir') . '/views';

        $environment->getLoader()->addPath($globalTemplateDir);
    }
}