code: @Override
      public boolean match(Statement s) {
          if (s.getObject() == null) {
              return false;
          }
          if (s.getObject().getTerm() == null) {
              return false;
          }
          final RelationshipType r = s.getRelationshipType();
          if (!r.isDirected()) {
              return true;
          }
          return false;
      }
docs: Returns {@code true} if the statement's {@link Statement#getObject()
  object} is non-null and its {@link Statement#getRelationshipType()
  relationship} does not match {@link RelationshipType#isDirected()}.