title: How to "lock" Vuetify v-list-item-group selection?
body: <p>I have a <a href="https://vuetifyjs.com/en/components/list-item-groups" rel="nofollow noreferrer"><code>v-list-item-group</code></a> for having a stateful list items. The thing is I want to <strong>disable altering</strong> the currently selected item once any is selected.</p>
  
  <p>To achieve that, I tried adding a <code>watch</code> on the selected item and reverting the <code>v-model</code> of the old value of it. However, it ends up in an infinite loop (you know, I assign new value inside its own watcher).</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;template&gt;
    &lt;v-list&gt;
      &lt;v-list-item-group v-model="model" :mandatory="!!model"&gt;
        &lt;v-list-item v-for="(item, i) in items" :key="`item-${i}`" :value="item"&gt;
          &lt;v-list-item-content&gt;
            &lt;v-list-item-title v-text="item"&gt;&lt;/v-list-item-title&gt;
          &lt;/v-list-item-content&gt;
        &lt;/v-list-item&gt;
      &lt;/v-list-item-group&gt;
    &lt;/v-list&gt;
  &lt;/template&gt;
  &lt;script&gt;
    export default {
      data: () =&gt; ({
        items: [
          'item1',
          'item2',
          'item3'
        ],
        model: null,
      }),
      watch: {
        model (val, oldVal) {
          // This logic will change the value and trigger watcher again and again
          this.val = oldVal
      }
    }
  &lt;/script&gt;
  </code></pre>
  
  <p>So, how to <strong>lock</strong> the selection of a `v-list-item-group? -apparently the snippet above is not the right way.</p>