code: function find(model) {
        var _this = this;
        var forceFetch = arguments[1] === undefined ? false : arguments[1];
        var record = this.records.get(model);
  
        if (record && !forceFetch) {
          return Promise.resolve(record);
        } else {
          model = this._ensureModel(model);
          return Promise.resolve(model.fetch()).then(function () {
            return _this.insert(model);
          });
        }
      }
docs: Find a specific model from the store or fetch it from the server and insert
  it into the store.
  
  @public
  @instance
  @method find
  @memberOf Storage
  @param {Number|String|Object|Backbone.Model} model - The model to find.
  @param {Boolean} forceFetch - Force fetch model from server.
  @returns {Promise} - A promise that will resolve to the model.