protected function checkToken($xml){
        if ($xml && $xml->NextToken && (string)$xml->HasNext != 'false' && (string)$xml->MoreResultsAvailable != 'false'){
            $this->tokenFlag = true;
            $this->options['NextToken'] = (string)$xml->NextToken;
        } else {
            unset($this->options['NextToken']);
            $this->tokenFlag = false;
        }
    }