I must be missing something. How can I use vuex mapState with multiple modules?

As far as understand, besides passing an object as argument, namespaced mapState can take two arguments: namespace and an array of object names denoting the members of modules. Like this

```
// an imcomplete vue
export default {
   computed: mapState('user', ['addresses', 'creditCards']) 
};

```

But what if i'd like to add objects from a second namespace to computed? e.g. vendor like this:

```
mapState('vendor', ['products', 'ratings']) 

```

Currently I am merging both mapState like this:

```
let userMapState = mapState('user', ['addresses', 'creditCards']); 
let vendorMapState = mapState ('vendor', ['products', 'ratings']);
let mergedMapStates = Object.assign({}, userMapState, vendorMapState);

```

And then:

```
// an imcomplete vue
export default {
    computed: mergedMapStates
};

```

It works, but it's hardly the right way to do it. Or is it?