### Question:
GroupInstanceDao { protected void delete(final Long... ids) { delete(Lists.newArrayList(ids)); } private  GroupInstanceDao(); List<GroupInstanceModel> query(); List<GroupInstanceModel> select(GroupInstanceModel filter); List<GroupInstanceModel> select(List<Long> groupIds); static final GroupInstanceDao INSTANCE; }### Answer:
@Test public void testDelete() { GroupInstanceModel groupInstance = newGroupInstance(); groupInstanceDao.insert(groupInstance); GroupInstanceModel copy1 = query(groupInstance); groupInstanceDao.delete(copy1.getId()); Assert.assertNull(query(groupInstance, 0)); }