@Test
public void testIsNotExpired() {

    Assert.assertFalse(Deadline.fromUnixMilliseconds(0).isNotExpired());
    Assert.assertFalse(Deadline.fromUnixMilliseconds(1).isNotExpired());
    Assert.assertTrue(Deadline.MAX_VALUE.isNotExpired());
    Assert.assertFalse(Deadline.MIN_VALUE.isNotExpired());
}