修复在iframe中运行时, 调用document.open()报错的问题

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@bd/core",
-  "version": "1.9.1",
+  "version": "1.9.2",
   "type": "module",
   "description": "百搭UI组件库的核心",
   "main": "dist/index.js",

src/index.js

@@ -183,7 +183,7 @@ export class Component extends HTMLElement {
   disconnectedCallback() {
     this[__children__]?.setConnected(false)
 
-    if (!document.body.contains(this)) {
+    if (!document.body?.contains(this)) {
       let $events = this.$events
       if ($events) {
         for (let name in $events) {