public static function writeXMLElement(XMLWriter $xml, $data)
 {
     foreach ($data as $key => $value) {
         if (preg_match('/(\\d+)/', $key)) {
             $key = 'key_' . $key;
         }
         if (is_array($value)) {
             $xml->startElement($key);
             Com_Icodeecono_Api_ResponseFormatter_XMLApiResponseFormatter::writeXMLElement($xml, $value);
             $xml->endElement();
             continue;
         }
         $xml->writeElement($key, $value);
     }
 }