public static EntityModel newModel(
     Version version, String name, String packageName, boolean render) {
   EntityModel model = MODELS.get(packageName + ".model." + name);
   if (model == null) {
     model = new EntityModel(version, name, packageName, render);
     MODELS.put(model.getFullName(), model);
   } else {
     model.newVersion(version);
   }
   return model;
 }