State accessor for nested state?

I have a state object like so:

```js
state: {
   something: {
      foo: 1
   }
}
```

However if I try to create a getter to `foo` like so:

```js
@State("something.foo")
public foo;
```

It doesnt do anything, I assume because it doesnt realise the `.` is meaning look in a child element, so is this a valid use case or a better approach to handling complex state objects?