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

        return url()->current().'?'.http_build_query(array_merge(\Request::all(), $params));
    }