private function parse($body)
  {
      parse_str($body, $response_array);
      if ($response_array['ACK'] == self::FAILURE) {
          $error_message = 'Error code ('.$response_array['L_ERRORCODE0'].")\n ".$response_array['L_SHORTMESSAGE0'].".\n Reason: ".$response_array['L_LONGMESSAGE0'];
          Merchant_Logger::error_log($error_message);
      }

      return $response_array;
  }