docs: public Observable<ServiceResponseWithHeaders<CloudTaskListSubtasksResult, TaskListSubtasksHeaders>> listSubtasksWithServiceResponseAsync(String jobId, String taskId, TaskListSubtasksOptions taskListSubtasksOptions) {
          if (this.client.batchUrl() == null) {
              throw new IllegalArgumentException("Parameter this.client.batchUrl() is required and cannot be null.");
          }
          if (jobId == null) {
              throw new IllegalArgumentException("Parameter jobId is required and cannot be null.");
          }
          if (taskId == null) {
              throw new IllegalArgumentException("Parameter taskId is required and cannot be null.");
          }
          if (this.client.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.client.apiVersion() is required and cannot be null.");
          }
          Validator.validate(taskListSubtasksOptions);
          String select = null;
          if (taskListSubtasksOptions != null) {
              select = taskListSubtasksOptions.select();
          }
          Integer timeout = null;
          if (taskListSubtasksOptions != null) {
              timeout = taskListSubtasksOptions.timeout();
          }
          UUID clientRequestId = null;
          if (taskListSubtasksOptions != null) {
              clientRequestId = taskListSubtasksOptions.clientRequestId();
          }
          Boolean returnClientRequestId = null;
          if (taskListSubtasksOptions != null) {
              returnClientRequestId = taskListSubtasksOptions.returnClientRequestId();
          }
          DateTime ocpDate = null;
          if (taskListSubtasksOptions != null) {
              ocpDate = taskListSubtasksOptions.ocpDate();
          }
          String parameterizedHost = Joiner.on(", ").join("{batchUrl}", this.client.batchUrl());
          DateTimeRfc1123 ocpDateConverted = null;
          if (ocpDate != null) {
              ocpDateConverted = new DateTimeRfc1123(ocpDate);
          }
          return service.listSubtasks(jobId, taskId, this.client.apiVersion(), this.client.acceptLanguage(), select, timeout, clientRequestId, returnClientRequestId, ocpDateConverted, parameterizedHost, this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponseWithHeaders<CloudTaskListSubtasksResult, TaskListSubtasksHeaders>>>() {
                  @Override
                  public Observable<ServiceResponseWithHeaders<CloudTaskListSubtasksResult, TaskListSubtasksHeaders>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponseWithHeaders<CloudTaskListSubtasksResult, TaskListSubtasksHeaders> clientResponse = listSubtasksDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }