public function add($parentexpr, $value, $name = "")
    {
        $get = $this->get($parentexpr);
        if ($parents =& $get) {

            foreach ($parents as &$parent) {
                $parent = is_array($parent) ? $parent : array();

                if ($name != "") {
                    $parent[$name] = $value;
                } else {
                    $parent[] = $value;
                }
            }

            return true;
        }

        return false;
    }