code: private void addRelationshipTriples(DOReader reader,
                                          URIReference objURI,
                                          Set<Triple> set)
              throws Exception {
          for (RelationshipTuple tuple : reader.getRelationships()) {
              set.add(tuple.toTriple(null));
          }
      }
docs: Adds all triples given by reader.getRelationships(null, null).
  <p>
  This includes everything in RELS-EXT and RELS-INT as well as the implicit
  basic content model assertion, if any.