code: public Observable<ResourceGroupInner> createOrUpdateAsync(String resourceGroupName, ResourceGroupInner parameters) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, parameters).map(new Func1<ServiceResponse<ResourceGroupInner>, ResourceGroupInner>() {
              @Override
              public ResourceGroupInner call(ServiceResponse<ResourceGroupInner> response) {
                  return response.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
  @return the observable to the ResourceGroupInner object