t1.setProperty(AbstractNode.owner, user1);
t1.setProperty(AbstractNode.owner, group1);
assertEquals(group1, t1.getProperty(AbstractNode.owner));
Ownership ownerRel = t1.getIncomingRelationship(PrincipalOwnsNode.class);
assertNotNull(ownerRel);
// Do additional low-level check here to ensure cardinality!
List<Relationship> incomingRels = Iterables.toList(t1.getNode().getRelationships(Direction.INCOMING, new PrincipalOwnsNode()));
assertEquals(1, incomingRels.size());