Set scrolling for the box

I checked various tutorials on the Internet , It doesn't work , Finally, I accidentally try to find out , The parent box was originally set overflow:scroll It's OK . Um. , It's amazing .

<div class="body-head" :style="curHeight">
                <test>
                    <transition-group tag="ul" class='slide-ul' name="list">
                        <template v-for="item, index in class_data">
                            <li class="body-head-item" :key="index">
                                {
    {
    item.name}}
                            </li>
                        </template> 
                    </transition-group>
                      
                </test>
            </div>

.body-head {
    
    width: 25%;
    background-color: pink;
    overflow: scroll;
}