title: Ngxs - State is undefined
body: <p>just started playing around ngxs and hit a road block.
  I don't know what I'm doing wrong, but I'm getting 'state is undefined' error.</p>
  
  <p><strong>Action:</strong></p>
  
  <pre><code>const prefix = "[Tutorial]";
  
  export class AddTutorial {
    static readonly type = `${prefix} Add Tutorial`;
  
    constructor(public payload: string) { }
  }
  </code></pre>
  
  <p><strong>State:</strong></p>
  
  <pre><code>export class TutorialStateModel {
    tutorial: any[]
  }
  
  @State&lt;TutorialStateModel&gt;({
    name: 'tutorial',
    defaults: {
      tutorial: [],
    }
  })
  export class TutorialState {
  
    @Action(AddTutorial)
    addTutorial({ getState, patchState }: StateContext&lt;TutorialStateModel&gt;, { payload }: AddTutorial) {
      const state = getState();
      patchState({
        tutorial: [...state.tutorial, payload]
      });
    }
  
  }
  </code></pre>
  
  <p>error points to: <code>const state = getState();</code></p>
  
  <p><strong>Component:</strong></p>
  
  <pre><code>  ngOnInit() {
      this.store.dispatch(new AddTutorial('Redux'));
    }
  </code></pre>