public function sortByUrl()
    {
        $params = $_GET;
        $isDesc = isset($params['sort_order']) && $params['sort_order'] != 'asc';
        if ($this->isCurrentSortField() && $isDesc) {
            $params['sort_order'] = 'asc';
        } else {
            $params['sort_order'] = 'desc';
        }
        $params['order_by'] = $this->field;

        return url()->current().'?'.http_build_query($params);
    }