constructor(

    private router: Router,

    private activatedRoute: ActivatedRoute,

  ) {}

    this.router.events

      .filter(event => event instanceof NavigationEnd)

      .map(() => this.activatedRoute)

      .map(route => {

        while (route.firstChild) route = route.firstChild;

        return route;

      })

      .filter(route => route.outlet === 'primary')

      .mergeMap(route => route.data)

      .subscribe((event) => this.titleService.setTitle(event['title']));