docs: public static Batch batchOfKeys( final Iterator<NodeKey> keys,
                                       final long nodeCount,
                                       final float score,
                                       final String workspaceName,
                                       final RepositoryCache repository ) {
          assert nodeCount >= -1;
          if (keys == null) return emptyBatch(workspaceName, 1);
          final NodeCache cache = repository.getWorkspaceCache(workspaceName);
          return batchOfKeys(keys, nodeCount, score, workspaceName, cache);
      }