protected function textpack()
    {
        $textpacks = $this->dir . '/textpacks';

        if (!file_exists($textpacks) || !is_dir($textpacks) || !is_readable($textpacks)) {
            return '';
        }

        if (($cwd = getcwd()) === false || !chdir($textpacks)) {
            return '';
        }

        $out = [];

        foreach ((array) glob('*.textpack', GLOB_NOSORT) as $file) {
            if (!is_file($file) || !is_readable($file)) {
                continue;
            }

            $file = file_get_contents($file);

            if (!preg_match('/^#@language|\n#@language\s/', $file)) {
                array_unshift($out, $file);
                continue;
            }

            $out[] =  $file;
        }

        chdir($cwd);
        return implode("\n", $out);
    }