code: private RootDocument save(final Root root) {
          final RootDocumentMongo rootdoc =
                  (RootDocumentMongo) toDocConverter.createGedDocument(root);
          try {
              repositoryManager.getRootDocumentRepository().save(rootdoc);
          } catch (DataAccessException e) {
              logger.error("Could not save root: " + root.getDbName(), e);
              return null;
          }
          return rootdoc;
      }
docs: Save the root to the database.
  @param root the root GED object
  @return the root document