docs: private Acknowledge startJobExecution(JobMasterId newJobMasterId) throws Exception {
  
  		validateRunsInMainThread();
  
  		checkNotNull(newJobMasterId, "The new JobMasterId must not be null.");
  
  		if (Objects.equals(getFencingToken(), newJobMasterId)) {
  			log.info("Already started the job execution with JobMasterId {}.", newJobMasterId);
  
  			return Acknowledge.get();
  		}
  
  		setNewFencingToken(newJobMasterId);
  
  		startJobMasterServices();
  
  		log.info("Starting execution of job {} ({}) under job master id {}.", jobGraph.getName(), jobGraph.getJobID(), newJobMasterId);
  
  		resetAndScheduleExecutionGraph();
  
  		return Acknowledge.get();
  	}