if (this.allowContainerDrop && this.isValidDropPoint({ ddel: this.tree.getRootNode().ui.elNode, node: this.tree.getRootNode() }, "append", dd, e, data)) {
            var targetNode = this.tree.getRootNode();       
            targetNode.ui.startDrop();
            var dropNode = data.node || (dd.getTreeNode ? dd.getTreeNode(data, targetNode, 'append', e) : null);
            return this.processDrop(targetNode, data, 'append', dd, e, dropNode);