ngOnDestroy() {
   this.autofill.stopMonitoring(this.firstName);
   this.autofill.stopMonitoring(this.lastName);
 }
 ngAfterViewInit() {
   this._autofill.monitor(this.firstName)
       .subscribe(e => this.firstNameAutofilled = e.isAutofilled);
   this._autofill.monitor(this.lastName)
       .subscribe(e => this.lastNameAutofilled = e.isAutofilled);
 }
 ngOnInit() {
   this.autofill.monitor(this.firstName)
       .subscribe(e => this.firstNameAutofilled = e.isAutofilled);
   this.autofill.monitor(this.lastName)
       .subscribe(e => this.lastNameAutofilled = e.isAutofilled);
 }
 ngOnDestroy() {
   this.autofill.stopMonitoring(this.firstName.nativeElement);
   this.autofill.stopMonitoring(this.lastName.nativeElement);
 }