code: private void preIngestIfNeeded(boolean firstRun,
                                     DOManager doManager,
                                     RDFName objectName) throws Exception {
          PID pid = new PID(objectName.uri.substring("info:fedora/".length()));
          boolean exists = doManager.objectExists(pid.toString());
          if (exists && firstRun) {
              logger.info("Purging old system object: {}", pid);
              Context context = ReadOnlyContext.getContext(null,
                                                           null,
                                                           null,
                                                           false);
              DOWriter w = doManager.getWriter(USE_DEFINITIVE_STORE,
                                               context,
                                               pid.toString());
              w.remove();
              try {
                  w.commit("Purged by Fedora at startup (to be re-ingested)");
                  exists = false;
              } finally {
                  doManager.releaseWriter(w);
              }
          }
          if (!exists) {
              logger.info("Ingesting new system object: {}", pid);
              InputStream xml = getStream("org/fcrepo/server/resources/"
                                          + pid.toFilename() + ".xml");
              Context context = ReadOnlyContext.getContext(null,
                                                           null,
                                                           null,
                                                           false);
              DOWriter w = doManager.getIngestWriter(USE_DEFINITIVE_STORE,
                                                     context,
                                                     xml,
                                                     Constants.FOXML1_1.uri,
                                                     "UTF-8",
                                                     null);
              try {
                  w.commit("Pre-ingested by Fedora at startup");
              } finally {
                  doManager.releaseWriter(w);
              }
          }
      }
docs: Ingests the given system object if it doesn't exist, OR if it
  exists, but this instance of Fedora has never been started.
  This ensures that, upon upgrade, the old system object
  is replaced with the new one.