code: private void unregisterInternal(final JobID id) {
  
  		// Use spin lock here
  		while (this.lockMap.putIfAbsent(id, LOCK_OBJECT) != null);
  
  		if (decrementReferenceCounter(id) == 0) {
  			this.libraryManagerEntries.remove(id);
  		}
  
  		this.lockMap.remove(id);
  	}
docs: Unregisters a job ID and releases the resources associated with it.
  
  @param id
  the job ID to unregister