code: public Observable<ServiceResponse<Page<AvailableServiceSkuInner>>> listSkusWithServiceResponseAsync(final String groupName, final String serviceName) {
          return listSkusSinglePageAsync(groupName, serviceName)
              .concatMap(new Func1<ServiceResponse<Page<AvailableServiceSkuInner>>, Observable<ServiceResponse<Page<AvailableServiceSkuInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<AvailableServiceSkuInner>>> call(ServiceResponse<Page<AvailableServiceSkuInner>> page) {
                      String nextPageLink = page.body().nextPageLink();
                      if (nextPageLink == null) {
                          return Observable.just(page);
                      }
                      return Observable.just(page).concatWith(listSkusNextWithServiceResponseAsync(nextPageLink));
                  }
              });
      }
docs: Get compatible SKUs.
  The services resource is the top-level resource that represents the Data Migration Service. The skus action returns the list of SKUs that a service resource can be updated to.
  
  @param groupName Name of the resource group
  @param serviceName Name of the service
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;AvailableServiceSkuInner&gt; object