@Test
void shouldReturnEmptyOptionalIfNoMatchedFormat() {

    final CompositeDateTimeParser parser = new CompositeDateTimeParser(
            new ZonedDateTimeParser(),
            new LocalDateTimeParser(ZoneOffset.UTC)
    );
    final Optional<Long> parsed = parser.getEpochMilli("2017-10-05T10:36:22UTC");
    assertThat(parsed)
            .isEmpty();
}