docs: public ServiceFuture<List<VirtualMachineScaleSetSkuInner>> listSkusAsync(final String resourceGroupName, final String vmScaleSetName, final ListOperationCallback<VirtualMachineScaleSetSkuInner> serviceCallback) {
          return AzureServiceFuture.fromPageResponse(
              listSkusSinglePageAsync(resourceGroupName, vmScaleSetName),
              new Func1<String, Observable<ServiceResponse<Page<VirtualMachineScaleSetSkuInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<VirtualMachineScaleSetSkuInner>>> call(String nextPageLink) {
                      return listSkusNextSinglePageAsync(nextPageLink);
                  }
              },
              serviceCallback);
      }