@Override
 public void validateRefRepresentation() throws Exception {
   super.validateRefRepresentation();
   assertPropEquals(
       "voided",
       getObject()
           .isVoided()); // note that the voided property is only present if the property is voided
 }
 @Override
 public void validateRefRepresentation() throws Exception {
   super.validateRefRepresentation();
 }
 @Override
 public void validateRefRepresentation() throws Exception {
   super.validateRefRepresentation();
   assertPropEquals("retired", getObject().getRetired());
   assertPropPresent("concept");
 }