### Question:
UcsRackDAO extends DefaultDAOBase<Integer, UcsRack> { public List<UcsRack> findAllUcsRacksByDatacenter(final Datacenter datacenter) { return findAllUcsRacksByDatacenter(datacenter, null); } UcsRackDAO();  UcsRackDAO(final EntityManager entityManager); List<UcsRack> findAllUcsRacksByDatacenter(final Datacenter datacenter); List<UcsRack> findAllUcsRacksByDatacenter(final Datacenter datacenter,
        final String filter); boolean existAnyOtherWithIP(final String ip); Criterion filterBy(final String filter);  }### Answer:
@Test public void findAllUcsRacksByDatacenter() { DatacenterGenerator datacenterGenerator = new DatacenterGenerator(getSeed()); UcsRackGenerator ucsRackGenerator = new UcsRackGenerator(getSeed()); Datacenter datacenter1 = datacenterGenerator.createUniqueInstance(); Datacenter datacenter2 = datacenterGenerator.createUniqueInstance(); UcsRack UcsRack2_1 = ucsRackGenerator.createInstance(datacenter2); UcsRack2_1.setName("ucsRack1"); UcsRack UcsRack2_2 = ucsRackGenerator.createInstance(datacenter2); UcsRack2_2.setName("ucsRack2"); ds().persistAll(datacenter1, datacenter2, UcsRack2_1, UcsRack2_2); UcsRackDAO dao = createDaoForRollbackTransaction(); List<UcsRack> ucsRacks = dao.findAllUcsRacksByDatacenter(reload(dao, datacenter1)); Assert.assertTrue(ucsRacks.isEmpty()); ucsRacks = dao.findAllUcsRacksByDatacenter(reload(dao, datacenter2)); try { assertEqualsPropertyForList(Rack.NAME_PROPERTY, ucsRacks, "ucsRack1", "ucsRack2"); } catch (Exception e) { fail(e.getMessage()); } }