@Override
    @Cacheable(value = RedisKeyConstants.MAIL_ACCOUNT, key = "#id", unless = "#result == null")
    public MailAccountDO getMailAccountFromCache(Long id) {
        return getMailAccount(id);
    }
@Test
    public void testGetMailAccountFromCache() {
        // mock 数据
        MailAccountDO dbMailAccount = randomPojo(MailAccountDO.class);
        mailAccountMapper.insert(dbMailAccount);// @Sql: 先插入出一条存在的数据
        // 准备参数
        Long id = dbMailAccount.getId();

        // 调用
        MailAccountDO mailAccount = mailAccountService.getMailAccountFromCache(id);
        // 断言
        assertPojoEquals(dbMailAccount, mailAccount);
    }