ElementUI中el-radio再次点击取消选中

ElementUI中el-radio再次点击取消选中

<el-radio-group v-model="radio">
       <el-radio :label="1" @click.native.prevent="radioClick(1)">备选项</el-radio>
     </el-radio-group>
//prevent阻止默认事件

data(){
    return{
       radio: '',
    }
}

radioClick (e) {
      e === this.radio? (this.radio = ''):(this.radio = e)
    }