title: Vuex store unwatch
body: <p>store.watch function returns the unwatch function as documentation described.</p>
  
  <p>I need to watch my state for <strong>once</strong>. So, can I call unwatch function inside the watch method second parameter callback function or should I do it somewhere else ?</p>
  
  <pre><code>var unwatch = this.$store.watch(
    state =&gt; state.foo,
    () =&gt; {
      someMethod();
      unwatch();  // Is this work ?
    }
  )
  </code></pre>
  
  <p><em>PS: I could not understand watcher state, with logging it to console.</em></p>