docs: public Observable<CloudTaskListSubtasksResult> listSubtasksAsync(String jobId, String taskId, TaskListSubtasksOptions taskListSubtasksOptions) {
          return listSubtasksWithServiceResponseAsync(jobId, taskId, taskListSubtasksOptions).map(new Func1<ServiceResponseWithHeaders<CloudTaskListSubtasksResult, TaskListSubtasksHeaders>, CloudTaskListSubtasksResult>() {
              @Override
              public CloudTaskListSubtasksResult call(ServiceResponseWithHeaders<CloudTaskListSubtasksResult, TaskListSubtasksHeaders> response) {
                  return response.body();
              }
          });
      }