public static function serialize(
        array $array,
        $rootName,
        $defaultTag = null,
        $standalone = null
    ) {
        $xmlVersion  = '1.0';
        $xmlEncoding = 'UTF-8';

        if (!is_array($array)) {
            return false;
        }

        $xmlw = new \XmlWriter();
        $xmlw->openMemory();
        $xmlw->startDocument($xmlVersion, $xmlEncoding, $standalone);

        $xmlw->startElement($rootName);

        self::_arr2xml($xmlw, $array, $defaultTag);

        $xmlw->endElement();

        return $xmlw->outputMemory(true);
    }