code: public Observable<Void> promoteAsync(String resourceGroupName, String clusterName, String scriptExecutionId) {
          return promoteWithServiceResponseAsync(resourceGroupName, clusterName, scriptExecutionId).map(new Func1<ServiceResponse<Void>, Void>() {
              @Override
              public Void call(ServiceResponse<Void> response) {
                  return response.body();
              }
          });
      }
docs: Promotes the specified ad-hoc script execution to a persisted script.
  
  @param resourceGroupName The name of the resource group.
  @param clusterName The name of the cluster.
  @param scriptExecutionId The script execution Id
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceResponse} object if successful.