private void addSupertypeFields(EntityType model, Set<EntityType> handled) {
   if (handled.add(model)) {
     for (Supertype supertype : model.getSuperTypes()) {
       EntityType entityType = context.allTypes.get(supertype.getType().getFullName());
       if (entityType != null) {
         addSupertypeFields(entityType, handled);
         supertype.setEntityType(entityType);
         model.include(supertype);
       }
     }
   }
 }