code: public ResourceGroupInner createOrUpdate(String resourceGroupName, ResourceGroupInner parameters) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, parameters).toBlocking().single().body();
      }
docs: Creates a resource group.
  
  @param resourceGroupName The name of the resource group to create or update.
  @param parameters Parameters supplied to the create or update a resource group.
  @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 ResourceGroupInner object if successful.