private JClass mapType(Filter filter) throws JClassAlreadyExistsException {
   if (!(filter.getOption() == null || filter.getOption().isEmpty())) {
     return getParamTypeEnum(filter);
   }
   String type = filter.getType();
   Class<?> typeCls = typeMap.get(type);
   checkState(typeCls != null, "Unexpected type: %s", type);
   return model.ref(typeCls);
 }