public static function get()
{
$loader = new Twig_Loader_Filesystem(BASE_PATH . '/views');
self::$twig = new Twig_Environment($loader, array('cache' => BASE_PATH . '/cache', 'debug' => true));
self::$twig->addGlobal("base_url", BASE_URL);
self::$twig->addGlobal("assets_url", ASSETS_URL);
self::$twig->addGlobal("flash", $_SESSION['slim.flash']);
return self::$twig;
}