code: public Observable<VirtualMachineScaleSetInner> getByResourceGroupAsync(String resourceGroupName, String vmScaleSetName) {
          return getByResourceGroupWithServiceResponseAsync(resourceGroupName, vmScaleSetName).map(new Func1<ServiceResponse<VirtualMachineScaleSetInner>, VirtualMachineScaleSetInner>() {
              @Override
              public VirtualMachineScaleSetInner call(ServiceResponse<VirtualMachineScaleSetInner> response) {
                  return response.body();
              }
          });
      }
docs: Display information about a virtual machine scale set.
  
  @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 VirtualMachineScaleSetInner object