protected function getRecursiveAncestry(Collection $all_results, $ids)
    {
        $all_results->merge($results = DB::table($this->hierarchyTable)->whereIn('term_id', $ids)->get());

        if (count($results)) {
            $this->getRecursiveAncestry($all_results, Arr::pluck($results, 'parent_id'));
        }
    }