title: Can not cancel current navigation and navigate elsewhere from root component
body: <p>When a user is not logged into my application which is equal to that there exists no <code>userToken</code> in the localStorage then I just want to redirect him to the login route.</p>
  <p>Lets say the user enters the route <code>/customers</code> then he should be redirected to the login screen when there exist no <code>userToken</code> in the local storage.</p>
  <p><strong><code>App.component.ts</code>:</strong></p>
  <pre><code>export class AppComponent
  {
    constructor(private routerService: RouterService, private router: Router, private authService: AuthenticationService)
    {
      if (!authService.isLoggedIn())
      {
        this.router.navigate(['/login']);
      }
    }
  }
  </code></pre>
  <p>The router navigate method is called but it is not navigating to the login screen, why not? The customers data on backend is tried to fetch, but I get a 401 in the server response. That means the code after... the root app component just continued to run.</p>