docs: @Nonnull
    @Nonempty
    public String onStartJob (@Nonnull final ILongRunningJob aJob, @Nullable final String sStartingUserID)
    {
      ValueEnforcer.notNull (aJob, "Job");
  
      // Create a new unique in-memory ID
      final String sJobID = GlobalIDFactory.getNewStringID ();
      final LongRunningJobData aJobData = new LongRunningJobData (sJobID, aJob.getJobDescription (), sStartingUserID);
      m_aRWLock.writeLocked ( () -> m_aRunningJobs.put (sJobID, aJobData));
      return sJobID;
    }