code: function get(req, key, next) {
    var id = req.session.id;
    console.log('You must register a new ' + 'get'.red + ' function with ' + 'node-weixin-settings'.red +
      ', and should not use this function in production!');
    if (this._ && this._[id] && this._[id][key]) {
      return next(this._[id][key]);
    }
    next(null);
  }
docs: WARN: these functions should be replaced in real production environment