KERNEL-6465 refactor: 补充属性

typescript/widget/multilayersingletree/multilayersingletree.leveltree.ts

@@ -2,6 +2,7 @@ import { Pane } from '../../base/pane'
 
 export declare class MultiLayerSingleLevelTree extends Pane {
     static xtype: string;
+    static EVENT_CHANGE: string;
 
     initTree(nodes: any, ...args: any[]): void;