code: function xss(req, res) {
    var agent = (req.headers['user-agent'] || '').toLowerCase();
  
    if (agent && (~agent.indexOf(';msie') || ~agent.indexOf('trident/'))) {
      setHeader(res, 'X-XSS-Protection', '0');
    }
  }
docs: Forcefully add x-xss-protection headers.
  
  @param {Request} req The incoming HTTP request.
  @param {Response} res The outgoing HTTP response.
  @api public