code: public Observable<AppServiceCertificateOrderInner> createOrUpdateAsync(String resourceGroupName, String certificateOrderName, AppServiceCertificateOrderInner certificateDistinguishedName) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, certificateOrderName, certificateDistinguishedName).map(new Func1<ServiceResponse<AppServiceCertificateOrderInner>, AppServiceCertificateOrderInner>() {
              @Override
              public AppServiceCertificateOrderInner call(ServiceResponse<AppServiceCertificateOrderInner> response) {
                  return response.body();
              }
          });
      }
docs: Create or update a certificate purchase order.
  Create or update a certificate purchase order.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @param certificateOrderName Name of the certificate order.
  @param certificateDistinguishedName Distinguished name to to use for the certificate order.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request