code: public Observable<AppServiceCertificateOrderInner> getByResourceGroupAsync(String resourceGroupName, String certificateOrderName) {
          return getByResourceGroupWithServiceResponseAsync(resourceGroupName, certificateOrderName).map(new Func1<ServiceResponse<AppServiceCertificateOrderInner>, AppServiceCertificateOrderInner>() {
              @Override
              public AppServiceCertificateOrderInner call(ServiceResponse<AppServiceCertificateOrderInner> response) {
                  return response.body();
              }
          });
      }
docs: Get a certificate order.
  Get a certificate order.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @param certificateOrderName Name of the certificate order..
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the AppServiceCertificateOrderInner object