old_contents: const Action = {
    create: function(req, res) {
      res.json({action: 'create'});
    }
  }
  module.exports = Action;
new_contents: 'use strict';
  
  let user = require('../user_model');
  
  const Action = {
  		create: function(req, res) {
  
  		let promise = user.create(req.body);
  		promise.then(succesHandler , errorHandler)
  
  		function succesHandler (user){
  			res.status(201).json(user);
  		}
  
  		function errorHandler (err) {
  			res.status(400).json(err);
  		}
    }
  }
  module.exports = Action;
  
subject: create action with promise is created