def test_expire_at(self):
""" Test expire_at """
ttl_dict = TTLDict(60)
ttl_dict['a'] = 100
ttl_dict['b'] = 123
self.assertEqual(ttl_dict['a'], 100)
self.assertEqual(ttl_dict['b'], 123)
self.assertEqual(len(ttl_dict), 2)
ttl_dict.expire_at('a', time.time())
self.assertRaises(KeyError, lambda: ttl_dict['a'])
self.assertEqual(len(ttl_dict), 1)
self.assertEqual(ttl_dict['b'], 123)
