code: public Date modifyDatastreamByReference(Context context,
                                              String pid,
                                              String datastreamID,
                                              String[] altIDs,
                                              String dsLabel,
                                              String mimeType,
                                              String formatURI,
                                              String dsLocation,
                                              String checksumType,
                                              String checksum,
                                              String logMessage,
                                              Date lastModifiedDate)
              throws ServerException {
          return worker.modifyDatastreamByReference(context,
                                                    pid,
                                                    datastreamID,
                                                    altIDs,
                                                    dsLabel,
                                                    mimeType,
                                                    formatURI,
                                                    dsLocation,
                                                    checksumType,
                                                    checksum,
                                                    logMessage,
                                                    lastModifiedDate);
      }
docs: Delegate to the JournalWorker.