text: module.exports = function xXssProtection(options) {
  
    if (options && options.setOnOldIE) {
  
      return function xXssProtection(req, res, next) {
        res.setHeader('X-XSS-Protection', '1; mode=block');
        next();
      };
  
    } else {
  
      return function xXssProtection(req, res, next) {
  
        var matches = /msie\s*(\d+)/i.exec(req.headers['user-agent']);
  
        var value;
        if (!matches || (parseFloat(matches[1]) >= 9)) {
          value = '1; mode=block';
        } else {
          value = '0';
        }
  
        res.setHeader('X-XSS-Protection', value);
        next();
  
      };
  
    }
  
  };
  