code: function(options) {
        var changing = this._changing;
        this._changing = true;
  
        // Generate the changes to be triggered on the model.
        var triggers = this._computeChanges(true);
  
        this._pending = !!triggers.length;
  
        for (var i = triggers.length - 2; i >= 0; i -= 2) {
          this.trigger('change:' + triggers[i], this, triggers[i + 1], options);
        }
  
        if (changing) return this;
  
        // Trigger a `change` while there have been changes.
        while (this._pending) {
          this._pending = false;
          this.trigger('change', this, options);
          this._previousAttributes = _.clone(this.attributes);
        }
  
        this._changing = false;
        return this;
      }
docs: Call this method to manually fire a `"change"` event for this model and a `"change:attribute"` event for each changed attribute. Calling this will cause all objects observing the model to update.