constructor(private _ol: ObserverLocator, private _loginService: LoginService, private _router: Router){
   this.accessCommand = new DelegateCommand<any>(this.access.bind(this), this.canExecuteAccess.bind(this));
   this._ol.getObserver(this, 'username').subscribe(this.inputChange.bind(this));
   this._ol.getObserver(this, 'password').subscribe(this.inputChange.bind(this));
 }

	addNew(): void {
		let contact = new Contact();
		contact.id = this.getId();
		contact.username = "username";
		contact.email = "e-mail";

		this.observerLocator.getObserver(contact, 'checked').subscribe(() => this.updateStorage());

		this.contacts.push(contact);
		this.updateStorage();
	}

		return () => {
			this.observerLocator.getObserver(context, property).unsubscribe(callback);
		}

		this.contacts.forEach((e, i) => {
			this.observerLocator.getObserver(e, 'checked').subscribe(() => this.updateStorage());
		});