gistfile1.js

// USER MODEL

var User = function (user) {
  this.user = user;
};

User.prototype.all = function (callback) {
  var User = this;
  var users = [];
  /* snip */
  callback(error, user);
};

User.prototype.save = function (callback) {
  var User = this
    , user = User.user;
  /* snip */
  callback(error, users);
};

User.prototype.get = function(user, callback) {
  var User = this;
  if (!user.id) user = {id: user};
  /* snip */
  User.user = user;
  callback(error, user);
};

module.exports = User;

// USER CONTROLLER

var User = require('models/users');

exports.index = function(req, res, next) {
  var user = new User();
  user.all(function (error, users));
};

exports.create = function(req, res, next) {
  var user = new User(req.body.user);
  user.save(function (error, user));
};