<template>  <v-apptheme="dark">    <v-containerclass="d-flex ga-8 justify-center flex-wrap"fluid>      <v-sheetwidth="400">        <v-treeviewv-model:selected="selected":items="items"item-title="name"item-value="id"select-strategy="classic"item-propsopen-allselectable        >          <template #append="{item }">            <v-switchv-model="item.detached"hide-details />          </template>        </v-treeview>        <pre>{{ selected }}</pre>      </v-sheet>    </v-container>  </v-app></template><script setup>import {ref }from'vue'constselected=ref([])constitems=ref([{    id:999,    name:'root',    children: [      {        id:1,        name:'item 1',        detached:true,        children: [          { id:11, name:'Test 1', detached:true },          { id:12, name:'Test 2' },        ],      },      { id:2, name:'item 2' },      { id:3, name:'item 3', detached:true },      { id:4, name:'item 4', detached:true },      { id:5, name:'item 5' },    ],  }])</script>