public static function structToString($struct, array $options = [])
    {
        $tb = new TomlBuilder();

        if ($struct instanceof \Traversable) {
            $struct = iterator_to_array($struct);
        } elseif (is_object($struct)) {
            $struct = get_object_vars($struct);
        } else {
            $struct = (array) $struct;
        }

        static::addValues($tb, $struct);

        return $tb->getTomlString();
    }