code: function (json, callback) {
  
      if (!json) {
        return;
      }
  
      // serialize if it wasn't already
      var serialized = (typeof json === 'string')
        ? JSON.parse(json)
        : json;
  
      if (!serialized || (serialized && !serialized.objects)) return;
  
      this.clear();
  
      // TODO: test this
      this.backgroundColor = serialized.background;
      this._enlivenDatalessObjects(serialized.objects, callback);
    }
docs: Populates canvas with data from the specified dataless JSON
  JSON format must conform to the one of `fabric.Canvas#toDatalessJSON`
  @method loadFromDatalessJSON
  @param {String} json JSON string
  @param {Function} callback Callback, invoked when json is parsed
  and corresponding objects (e.g: fabric.Image)
  are initialized
  @return {fabric.Canvas} instance
  @chainable