code: public Iterator<Node> getVersions(final Graph graph,
          final Node subject) {
          // Mementos should be ordered by date so use the getOrderedVersions.
          return getOrderedVersions(graph, subject, CONTAINS.asResource());
      }
docs: Return an iterator of Triples for versions.
  
  @param graph the graph
  @param subject the subject
  @return iterator