)             .concatMap(new Func0<ServiceResponse<Page<FirewallPolicyInner>>, Observable<ServiceResponse<Page<FirewallPolicyInner>>>>() {                 @Override                 public Observable<ServiceResponse<Page<FirewallPolicyInner>>> call(ServiceResponse<Page<FirewallPolicyInner>> page) {                     String nextPageLink = page.body().nextPageLink();                     if (nextPageLink == null) {                         return Observable.just(page);                     }                     return Observable.just(page).concatWith(listNextWithServiceResponseAsync(nextPageLink));                 }             });     }      /**      * Gets all the Firewall Policies in a subscription.      *      * @throws IllegalArgumentException thrown if parameters fail the validation      * @return the PagedList&lt;FirewallPolicyInner&gt; object wrapped in {@link ServiceResponse} if successful.      */     public Observable<ServiceResponse<Page<FirewallPolicyInner>>> list