private function updateTreeNatively($nodeUid, $classname, $leftnode = 1, $level = 0)
    {
        $node = new \StdClass();
        $node->uid = $nodeUid;
        $node->leftnode = $leftnode;
        $node->rightnode = $leftnode + 1;
        $node->level = $level;

        $start = 0;
        $numChildren = $this->getCountChildren($nodeUid, $classname);
        while ($start < $numChildren) {
            foreach ($children = $this->getNodeChildren($nodeUid, $classname, $start, $this->step) as $child_uid) {
                $child = $this->updateTreeNatively($child_uid, $classname, $leftnode + 1, $level + 1);
                $node->rightnode = $child->rightnode + 1;
                $leftnode = $child->rightnode;
                unset($child);
            }
            unset($children);
            $start += $this->step;
        }

        $this->updatePageNodes($node->uid, $node->leftnode, $node->rightnode, $node->level, $classname);

        return $node;
    }