code: public Observable<Page<VirtualMachineScaleSetSkuInner>> listSkusAsync(final String resourceGroupName, final String vmScaleSetName) {
          return listSkusWithServiceResponseAsync(resourceGroupName, vmScaleSetName)
              .map(new Func1<ServiceResponse<Page<VirtualMachineScaleSetSkuInner>>, Page<VirtualMachineScaleSetSkuInner>>() {
                  @Override
                  public Page<VirtualMachineScaleSetSkuInner> call(ServiceResponse<Page<VirtualMachineScaleSetSkuInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Gets a list of SKUs available for your VM scale set, including the minimum and maximum VM instances allowed for each SKU.
  
  @param resourceGroupName The name of the resource group.
  @param vmScaleSetName The name of the VM scale set.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;VirtualMachineScaleSetSkuInner&gt; object