public function appendXML(SimpleXMLElement $append)
    {
        if (strlen(trim((string) $append)) == 0) {
            $xml = $this->addChild($append->getName());
            foreach ($append->children() as $child) {
                $xml->appendXML($child);
            }
        } else {
            $xml = $this->addChild($append->getName(), (string) $append);
        }
        foreach ($append->attributes() as $n => $v) {
            $xml->addAttribute($n, $v);
        }
    }