@Test
public void validateSelectProductOfferingStepEmptyProductIdShouldFail() {

    formBean.validateSelectProductOfferingStep(validationContext);
    MessageContext messageContext = validationContext.getMessageContext();
    Message[] messages = messageContext.getAllMessages();
    Assert.assertEquals(1, messages.length);
    Message message = messages[0];
    Assert.assertEquals("productId", message.getSource());
    verifyErrorMessage(NotNull.class, message);
}