code: private void registerExecutingJob(long jobExecutionId, BatchJobWorkUnit workUnit) {
  
          if (executingJobs.containsKey(jobExecutionId)) {
              throw new IllegalStateException("Already have entry in executingJobs map for job exec id = " + jobExecutionId);
          }
  
          executingJobs.put(jobExecutionId, workUnit);
      }
docs: /*
  stop all jobs
  - for each TLJ: stop job