DurationValidatorTest - Refactored

@Test
public void returnsASetOfErrorsForAnObject() throws Exception {
    assertThat(Locale.getDefault().getLanguage()).isEqualTo("en");

    final Collection<String> errors =
        ConstraintViolations.format(validator.validate(new Example()));

    assertThat(errors)
        .containsOnly(
            "outOfRange must be between 10 MINUTES and 30 MINUTES",
            "tooBig must be less than or equal to 30 SECONDS",
            "tooBigExclusive must be less than 30 SECONDS");
}