docs: public Observable<Void> updateAsync(String jobId, String taskId, TaskConstraints constraints, TaskUpdateOptions taskUpdateOptions) {
          return updateWithServiceResponseAsync(jobId, taskId, constraints, taskUpdateOptions).map(new Func1<ServiceResponseWithHeaders<Void, TaskUpdateHeaders>, Void>() {
              @Override
              public Void call(ServiceResponseWithHeaders<Void, TaskUpdateHeaders> response) {
                  return response.body();
              }
          });
      }