### Question:
UserDao { public void deleteById(Integer id) { mongoTemplate.remove(new Query(Criteria.where("_id").is(id)), UserDO.class); }  void insert(UserDO entity); void updateById(UserDO entity); void deleteById(Integer id); UserDO findById(Integer id); UserDO findByUsername(String username); List<UserDO> findAllById(List<Integer> ids);  }### Answer:
@Test public void testDelete() { userDao.deleteById(1); }