View view = new View();
ValidationErrors details = new ValidationErrors();
details.setSummary(new LocalizableMessage("summaryKey1", "summaryText1"));
details.addMessage("detailKey1", "field1", "detailText1");
details.addMessage("detailKey2", "field2", "detailText2");
details.addMessage("detailKey3", "field3", "detailText3");
InvalidDataException error = new InvalidDataException("message", details);
ValidationUtils.getInstance().showValidationError(view, error, "style");
assertTrue(view.validationErrorWidget.isVisible());
assertEquals("__summaryKey1", view.validationErrorWidget.getErrorSummary());
assertEquals(3, view.validationErrorWidget.getErrorList().size());