code: public Date[] purgeDatastream(Context context,
                                    String pid,
                                    String datastreamID,
                                    Date startDT,
                                    Date endDT,
                                    String logMessage) throws ServerException {
          return worker.purgeDatastream(context,
                                        pid,
                                        datastreamID,
                                        startDT,
                                        endDT,
                                        logMessage);
      }
docs: Delegate to the JournalWorker.