import ‘rxjs/add/operator/filter‘;import ‘rxjs/add/operator/map‘;import ‘rxjs/add/operator/mergeMap‘;import { Component, OnInit } from ‘@angular/core‘;import { Router, NavigationEnd, ActivatedRoute } from ‘@angular/router‘;import { Title } from ‘@angular/platform-browser‘;@Component({...})export class AppComponent implements OnInit {  constructor(    private router: Router,    private activatedRoute: ActivatedRoute,    private titleService: Title  ) {}  ngOnInit() {    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‘]));  }}