public function getTwig()
    {
        if (is_null($this->_twig)) {
            $this->_twig = new Twig_Environment(
                new Twig_Loader_Filesystem($this->_paths),
                [
                    'debug' => true,
                ]
            );
            $this->_twig->addExtension(new Twig_Extension_Debug());
            $this->_twig->addExtension(new SlickTwigExtension());
        }
        return $this->_twig;
    }