### Question:
AcceptHeaderValidatorImpl extends AbstractHeaderValidatorImpl implements TransactionListHeaderValidator { @Override public MessageError validate(Map<String, String> headers, MessageError messageError) { String header = headers.get(getHeaderName()); if (Objects.nonNull(header) && StringUtils.isBlank(header)) { errorBuildingService.enrichMessageError(messageError, TppMessageInformation.of(FORMAT_ERROR_BLANK_HEADER, getHeaderName())); } return messageError; } @Autowired  AcceptHeaderValidatorImpl(ErrorBuildingService errorBuildingService); @Override MessageError validate(Map<String, String> headers, MessageError messageError);  }### Answer:
@Test void validate_headerIsNotPresented_success() { validator.validate(headers, messageError); assertTrue(messageError.getTppMessages().isEmpty()); }