Have any example to use `Meteor - Vue - SRR`

VueJS
1

I follow to use Meteor - Vue SSR via (Meteor Vue Guaide).
But don’t understand.

Vue.mixin({
  beforeMount () {
    const { asyncData } = this.$options
    if (asyncData) {
      // assign the fetch operation to a promise
      // so that in components we can do `this.dataPromise.then(...)` to
      // perform other tasks after data is ready
      this.dataPromise = asyncData({
        store: this.$store,
        route: this.$route
      })
    }
  }
})
----------
export default {
  computed: {
    fooCount () {
      return this.$store.state.foo.count
    }
  },

  // Server-side only
  serverPrefetch () {
    this.registerFoo()
    return this.fooInc()
  },

Could help me for more detail or example???