private void then_ValidationShouldFailWithErrorMessage(String expectedIdValidationMessage) {
   try {
     _product.validate();
     then_AnExceptionShoulBeRaised();
   } catch (ValidationFailure vf) {
     // Then
     assertThat(vf.getMessage(), equalTo(expectedIdValidationMessage));
   }
 }
 private void then_TheProductShouldPassValidating() {
   _product.validate();
 }