public function makeGap($cut, $height)
    {
        $params = compact('cut', 'height');

        $query = $this->toBase()->whereNested(function (Query $inner) use ($cut) {
            $inner->where($this->model->getLftName(), '>=', $cut);
            $inner->orWhere($this->model->getRgtName(), '>=', $cut);
        });

        return $query->update($this->patch($params));
    }