private enum Validator {
    NON_CACHING_WITH_CONSTRUCTOR_CHECK(nonCachingWithConstructorCheckValidator()),
    NON_CACHING_WITHOUT_CONSTRUCTOR_CHECK(nonCachingWithoutConstructorCheckValidator()),
    WEAK_SET(weakSetValidator()),
    ;

    final GetCheckedTypeValidator validator;

    Validator(GetCheckedTypeValidator validator) {
      this.validator = validator;
    }
  }

  private enum Result {