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