### Question:
UserFriendServiceImpl implements UserFriendService { @Override public boolean updateUserFriend(UserFriend userFriend) { userFriend.setModifiedTime(new Date()); return userFriendDao.updateUserFriend(userFriend); }  @Override List<UserFriend> listByUid(Long uid, Integer page, Integer limit); @Override UserFriend findByUidAndFriendUid(Long uid, Long friendUid); @Override boolean insertUserFriendAll(List<UserFriend> userFriends); @Override boolean updateUserFriend(UserFriend userFriend); @Override boolean deleteByUidAndFriendUid(Long uid, Long friendUid);  }### Answer:
@Test public void updateUserFriend() { }