public function ChildrenOf($parentRef)
    {
        $parent = SiteTree::get_by_link($parentRef);

        if (!$parent && is_numeric($parentRef)) {
            $parent = DataObject::get_by_id(SiteTree::class, $parentRef);
        }

        if ($parent) {
            return $parent->Children();
        }
        return null;
    }