old_contents: 'use strict';
  
  let express = require('express'),
      controller = require('./folders'),
      router = express.Router();
  
  console.log(controller);
  
  router.post('/add', controller.add);
  
  
  module.exports = router;
new_contents: 'use strict';
  
  let express = require('express'),
      controller = require('./folders'),
      router = express.Router();
  
  router.post('/add', controller.add);
  
  
  module.exports = router;
subject: refactor code