[2185] [Question] Does head function not support mixin?

Because each page page needs to configure their own head information,So I declare head in mixin. But as shown in the figure below, the code does not take effect. ~/plugins/xxx

const MyPlugin = {
  install (Vue, options) {
    Vue.mixin({
      head () {
        .....
        return {
          title: tkd['title'],
          meta: [
            {
              hid: 'keywords', name: 'keywords', content: tkd['keywords']
            },
            {
              hid: 'description', name: 'description', content: tkd['description']
            }
          ]
        }
      }
    })
  }
}

Vue.use(MyPlugin)

Does head not support mixin?