private function _extractResponseHeaderMetadata($rawHeaders){
        $inputHeaders = preg_split("/\r\n|\n|\r/", $rawHeaders);
        $headers = array();
        $headers['x-mws-request-id'] = null;
        $headers['x-mws-response-context'] = null;
        $headers['x-mws-timestamp'] = null;
        $headers['x-mws-quota-max'] = null;
        $headers['x-mws-quota-remaining'] = null;
        $headers['x-mws-quota-resetsOn'] = null;

        foreach ($inputHeaders as $currentHeader) {
            $keyValue = explode (': ', $currentHeader);
            if (isset($keyValue[1])) {
                list ($key, $value) = $keyValue;
                if (isset($headers[$key]) && $headers[$key]!==null) {
                    $headers[$key] = $headers[$key] . "," . $value;
                } else {
                    $headers[$key] = $value;
                }
            }
        }
 
        require_once(dirname(__FILE__) . '/Model/ResponseHeaderMetadata.php');
        return new MarketplaceWebServiceOrders_Model_ResponseHeaderMetadata(
          $headers['x-mws-request-id'],
          $headers['x-mws-response-context'],
          $headers['x-mws-timestamp'],
          $headers['x-mws-quota-max'],
          $headers['x-mws-quota-remaining'],
          $headers['x-mws-quota-resetsOn']);
    }