title: How to use vuex namespaced getters with arguments?
body: <p>I have issue when Im using vuex.</p>
  
  <p>I have getters in namespaced module and I cant figurę out how to get the data with Ii when Im passing some arguments. </p>
  
  <pre><code>this.$store.getters.feeders.getFeedersById(id)
  </code></pre>
  
  <p>And in maper.</p>
  
  <pre><code>...mapGetters({
     feeders: ['feeders/getFeedersById'](this.id)
  </code></pre>
  
  <p>Getting error like this getter is not a function. What else shoudl I do?</p>