### Question:
GroupOperationDao { protected void delete(GroupOperationModel groupOperation) { delete(Lists.newArrayList(groupOperation)); } private  GroupOperationDao(); List<GroupOperationModel> query(); static final GroupOperationDao INSTANCE; }### Answer:
@Test public void testDelete() throws Exception { GroupOperationModel groupOperation = newGroupOperation(); groupOperationDao.insertOrUpdate(groupOperation); assertGroupOperation(groupOperation, query(groupOperation)); groupOperationDao.delete(groupOperation); Assert.assertNull(query(groupOperation)); }