Element-UI cascader级联选择器，任意选择（父级也可）

<!-- Test.vue -->
<template>
  <div style="display: flex; justify-content: center; margin-top: 200px;">
    <el-cascader ref="cascader" v-model="addrCode" :options="options" :props="{ checkStrictly: true, expandTrigger: 'hover