:::demo 示例

```html
<template>
    <div>
        <v-checkbox-group v-model="checkedCities2" is-vertical-show>
            <v-checkbox v-for="city in cities2" :label="city" :key="city">{{city}}</v-checkbox>
        </v-checkbox-group>
    </div>
</template>

<script>
    export default{
        data() {
            return {
                checkedCities2:['上海', '北京'],
                cities2:['上海', '北京', '广州', '深圳']
            };
        },
    }
</script>
```
:::