/** {@inheritDoc} */
 @Override
 public int hashCode() {
   return def.hashCode() + retention.hashCode();
 }
 /**
  * Compare everything but the ordinary {@link AnnotationDef}. For the convenience of {@link
  * TLAnnotation#equals(TLAnnotation)}.
  */
 boolean extraEquals(/*@NonNull*/ TLAnnotationDef o) {
   return retention.equals(o.retention);
 }