let duplicate = request.clone({
headers: new HttpHeaders({
    'Authorization': token
})

getValidToken(): any {
    return new Promise(resolve => {
      this.secureStorage.create('login_data').then((storage: SecureStorageObject) => {
        storage.get('token').then(data => {
          resolve(data);
        });
      });
    });
  }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    this.loginProvider = this.injector.get(LoginProvider);  // avoid cyclic dependency errors, cf. https://github.com/angular/angular/issues/18224
    this.getValidToken().then(token => {
      let duplicate = request.clone({
        headers: new HttpHeaders({
          'Authorization': token
        })
      });
      return next.handle(duplicate).do((event: HttpEvent<any>) => null, (error: any) => {
        if (error instanceof HttpErrorResponse)
        if (error.status === 401 || error.status === 403)
        /* redirect to login, username/password do not match anymore */
        this.injector.get(NavController).setRoot(LogoutPage);
      });
    })
  }