class NotBlacklistValidator implements Validator<NotBlacklist> {
    public static final NotBlacklistValidator instance = new NotBlacklistValidator();
    private NotBlacklistChecker checker = (anno, ctx) -> false;

    public void setChecker(NotBlacklistChecker checker) {
        if (checker != null) {
            this.checker = checker;
        }
    }

    @Override
    public String message(NotBlacklist anno) {
        return anno.message();
    }

    @Override
    public Class<?>[] groups(NotBlacklist anno) {
        return anno.groups();
    }

    @Override
    public Result validateOfContext(Context ctx, NotBlacklist anno, String name, StringBuilder tmp) {<FILL_FUNCTION_BODY>}
}

        if (checker.check(anno, ctx)) {
            return Result.succeed();
        } else {
            return Result.failure(403);
        }
    
<no_super_class>