code: function corsPrefetch(req, res, next) {
  	res.header('Access-Control-Allow-Origin', req.headers.origin);
  	res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
  	res.header('Access-Control-Allow-Headers', 'Content-Type, *');
  	res.setHeader('Access-Control-Allow-Credentials', 'true');
  
  	if (req.method === 'OPTIONS') {
  		res.sendStatus(200);
  		return;
  	}
  
  	next();
  }
docs: This middleware stands for prevent blocking
  in latest Firefox and Chrome because of
  prefetch checks
  @param req express.request
  @param res express.response
  @param next next experss middleware