),             new Func0<String, Observable<ServiceResponse<Page<FirewallPolicyInner>>>>() {                 @Override                 public Observable<ServiceResponse<Page<FirewallPolicyInner>>> call(String nextPageLink) {                     return listNextSinglePageAsync(nextPageLink);                 }             },             serviceCallback);     }      /**      * Gets all the Firewall Policies in a subscription.      *      * @throws IllegalArgumentException thrown if parameters fail the validation      * @return the observable to the PagedList&lt;FirewallPolicyInner&gt; object      */     public Observable<Page<FirewallPolicyInner>> list