@Override
    public ZonedDateTime createdAt() {
        return ZonedDateTime.parse("2016-11-22T17:45:00Z");
    }
@Test
    public void createdAt() throws Exception {
        // Test the date to detect accidental changes to it.
        assertThat(migration.createdAt()).isEqualTo(ZonedDateTime.parse("2016-11-22T17:45:00Z"));
    }