Exhibit exhibit = context.newObject(Exhibit.class);
exhibit.setOpeningDate(new Date());
exhibit.setClosingDate(new Date());
ValidationResult result = new ValidationResult();
exhibit.validateForSave(result);
assertTrue("Validation of 'toGallery' should've failed.", result.hasFailures());
assertTrue(result.hasFailures(exhibit));
List<ValidationFailure> failures = result.getFailures();