### Question:
AIS400ErrorMapper extends Psd2ErrorMapper<MessageError, Error400NGAIS> { @Override public HttpStatus getErrorStatus() { return HttpStatus.BAD_REQUEST; }  @Override Function<MessageError, Error400NGAIS> getMapper(); @Override HttpStatus getErrorStatus();  }### Answer:
@Test void getErrorStatus_shouldReturn400() { HttpStatus errorStatus = ais400ErrorMapper.getErrorStatus(); assertEquals(HttpStatus.BAD_REQUEST, errorStatus); }