code: function() {
        // Need to check if each view is attached because there is no guarentee that if parent is attached, child is attached.
        if (!this.__attachedCallbackInvoked) {
          this.trigger('before-attached-callback');
          this._attached();
          this.__attachedCallbackInvoked = true;
          _.each(this.getTrackedViews(), function(view) {
            if (view.isAttachedToParent()) {
              view.__invokeAttached();
            }
          });
        }
      }
docs: Call this method when a view is attached to the DOM. It is recursive to child views, but checks whether each child view is attached.
  @method __invokeAttached
  @private