### Question:
IbanValidator { public void validate(String iban, @NotNull MessageError messageError) { if (ibanValidationEnabled != null && BooleanUtils.isNotTrue(ibanValidationEnabled)) { log.info("IBAN validation is disabled."); return; } if (StringUtils.isNotBlank(iban) && !isValidIban(iban)) { errorBuildingService.enrichMessageError(messageError, TppMessageInformation.of(FORMAT_ERROR_INVALID_FIELD, "IBAN")); } }  void validate(String iban, @NotNull MessageError messageError);  }### Answer:
@Test void validate_success() { validator.validate("DE15500105172295759744", messageError); assertTrue(messageError.getTppMessages().isEmpty()); }
@Test void validate_invalidIban() { validator.validate("123", messageError); assertFalse(messageError.getTppMessages().isEmpty()); assertEquals(MessageErrorCode.FORMAT_ERROR_INVALID_FIELD, messageError.getTppMessage().getMessageErrorCode()); }
@Test void validate_validationDisabled() { ReflectionTestUtils.setField(validator, "ibanValidationEnabled", false); validator.validate("123", messageError); assertTrue(messageError.getTppMessages().isEmpty()); }