code: public VirtualMachineScaleSetInner createOrUpdate(String resourceGroupName, String vmScaleSetName, VirtualMachineScaleSetInner parameters) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, vmScaleSetName, parameters).toBlocking().last().body();
      }
docs: Create or update a VM scale set.
  
  @param resourceGroupName The name of the resource group.
  @param vmScaleSetName The name of the VM scale set to create or update.
  @param parameters The scale set object.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the VirtualMachineScaleSetInner object if successful.