protected function collateDescendants($recordIDs, &$collator)
    {

        $children = SiteTree::get()->filter(['ParentID' => $recordIDs])->column();
        if ($children) {
            foreach ($children as $item) {
                $collator[] = $item;
            }
            $this->collateDescendants($children, $collator);
            return true;
        }
        return false;
    }