code: function(view, childView, options) {
          var buffer = view.buffer;
          var _childViews = view._childViews;
  
          childView = view.createChildView(childView, options);
          if (!_childViews.length) { _childViews = view._childViews = _childViews.slice(); }
          _childViews.push(childView);
  
          if (!childView._morph) {
            buffer.pushChildView(childView);
          }
  
          view.propertyDidChange('childViews');
  
          return childView;
        }
docs: when a view is rendered in a buffer, appending a child view will render that view and append the resulting buffer into its buffer.