Airship\Cabin\Bridge\Blueprint\Blog::getAllSeriesParents PHP Method

    public function getAllSeriesParents(array $seriesIds, int $depth = 0) : array
    {
        if ($depth > 100) {
            return [];
        }
        $ret = [];
        foreach ($seriesIds as $ser) {
            $parents = $this->db->first('SELECT parent FROM hull_blog_series_items WHERE series = ?', $ser);
            if (!empty($parents)) {
                foreach ($this->getAllSeriesParents($parents, $depth + 1) as $par) {
                    $ret[] = $par;
                }
            }
            $ret[] = $ser;
        }
        return $ret;
    }