think\response\Xml::xmlEncode PHP Метод

    protected function xmlEncode($data, $root, $item, $attr, $id, $encoding)
    {
        if (is_array($attr)) {
            $array = [];
            foreach ($attr as $key => $value) {
                $array[] = "{$key}=\"{$value}\"";
            }
            $attr = implode(' ', $array);
        }
        $attr = trim($attr);
        $attr = empty($attr) ? '' : " {$attr}";
        $xml = "<?xml version=\"1.0\" encoding=\"{$encoding}\"?>";
        $xml .= "<{$root}{$attr}>";
        $xml .= $this->dataToXml($data, $item, $id);
        $xml .= "</{$root}>";
        return $xml;
    }