code: public void scheduleAsync(@NonNull final JobScheduledCallback callback) {
          JobPreconditions.checkNotNull(callback);
          JobConfig.getExecutorService().execute(new Runnable() {
              @Override
              public void run() {
                  try {
                      int jobId = schedule();
                      callback.onJobScheduled(jobId, getTag(), null);
                  } catch (Exception e) {
                      callback.onJobScheduled(JobScheduledCallback.JOB_ID_ERROR, getTag(), e);
                  }
              }
          });
      }
docs: Helper method to schedule a request on a background thread. This is helpful to avoid IO operations
  on the main thread. The callback notifies you about the job ID or a possible failure.
  
  @param callback The callback which is invoked after the request has been scheduled.