@Test public void findByOwner(){
  Group group=groupDAO.find(6L);
  assertNotNull("did not find expected group",group);
  User user=userDAO.find(5L);
  assertNotNull("did not find expected user",user);
  assertEquals(user,group.getUserOwner());
  List ownedGroups=groupDAO.findOwnedByUser(user.getKey());
  assertFalse(ownedGroups.isEmpty());
  assertEquals(1,ownedGroups.size());
  assertTrue(ownedGroups.contains(group));
}