private void invalidEmployee(File fileInvalid) throws Exception {

    JAXBException exception = null;
    toggleDriversGroupOnOff();

    /* Marshal w/ validation - doesn't pass (we want to check that). */
    try {
      marshallerValidOn.marshal(employeeInvalid, fileInvalid);
    } catch (JAXBException e) {
      exception = e;
    }
    assertNotNull(exception);
    assertEquals(
        String.valueOf(BeanValidationException.CONSTRAINT_VIOLATION), exception.getErrorCode());
    if (DEBUG) System.out.println(exception.getMessage());
    checkValidationMessages(marshallerValidOn.getConstraintViolations(), violationMessages);

    /* Marshal w/o validation - creates file for the next part of the test. */
    marshallerValidOff.marshal(employeeInvalid, fileInvalid);
    Set<ConstraintViolationWrapper<Object>> marshalCV =
        marshallerValidOff.getConstraintViolations();
    assertTrue(marshalCV.isEmpty());

    /* Unmarshal w/ validation - doesn't pass (we want to check that). */
    exception = null;
    try {
      unmarshallerValidOn.unmarshal(fileInvalid);
    } catch (JAXBException e) {
      exception = e;
    }
    assertNotNull(exception);
    assertEquals(
        String.valueOf(BeanValidationException.CONSTRAINT_VIOLATION), exception.getErrorCode());
    if (DEBUG) System.out.println(exception.getMessage());
    checkValidationMessages(unmarshallerValidOn.getConstraintViolations(), violationMessages);

    /* Unmarshal w/ validation AND no groups - doesn't pass (we want to check that). */
    toggleDriversGroupOnOff();
    exception = null;

    try {
      unmarshallerValidOn.unmarshal(fileInvalid);
    } catch (JAXBException e) {
      exception = e;
    }
    assertNotNull(exception);
    assertEquals(
        String.valueOf(BeanValidationException.CONSTRAINT_VIOLATION), exception.getErrorCode());
    if (DEBUG) System.out.println(exception.getMessage());
    checkValidationMessages(
        unmarshallerValidOn.getConstraintViolations(), violationMessagesWithoutGroup);
    toggleDriversGroupOnOff();

    /* Unmarshal w/o validation - testing that invalid objects are correctly unmarshalled when validation is NONE. */
    Employee employeeUnm = (Employee) unmarshallerValidOff.unmarshal(fileInvalid);
    assertTrue(unmarshallerValidOff.getConstraintViolations().isEmpty());

    /* Final check that the validation feature did not affect original behavior of JAXB. */
    assertEquals(employeeInvalid, employeeUnm);
  }
  private void validEmployee(File file) throws Exception {

    toggleDriversGroupOnOff();

    marshallerValidOn.marshal(employeeValid, file);
    assertTrue(marshallerValidOn.getConstraintViolations().isEmpty());

    Employee employeeUnm = (Employee) unmarshallerValidOn.unmarshal(file);
    assertTrue(unmarshallerValidOn.getConstraintViolations().isEmpty());

    assertEquals(employeeValid, employeeUnm);
  }