public function add($name, $value = null)
    {
        if (empty($name)) {
            return $this;
        }

        $params = (!is_array($name) ? array($name => $value) : $name);

        $query = $this->query(true);

        foreach ($params as $key => $val) {
            if (empty($val)) {
                unset($query[$key]);
            } elseif (!empty($val)) {
                $query[$key] = $val;
            }
        }

        $query              = http_build_query($query);
        $this->url['query'] = $query;

        return $this;
    }