@Override
 public String toString() {
   return "Output parameter, identifier='"
       + getIdentifier()
       + "', title='"
       + definition.getTitle()
       + "', abstract='"
       + definition.getAbstract()
       + "'";
 }
 @Override
 public CodeType getIdentifier() {
   return new CodeType(
       definition.getIdentifier().getValue(), definition.getIdentifier().getCodeSpace());
 }