private static function validate()
    {
        $me = get_called_class();
        if (!isset(self::$consts[$me])) {
            $constants = self::constants();
            if (!isset($constants["__DEFAULT"])) {
                self::toss(
                    "UndefinedConstantException",
                    "Class {me} does have a __DEFAULT constant."
                );
            }

            foreach($constants as $name => $value) {
                if ("__DEFAULT" !== $name && $name !== $value) {
                    self::toss(
                        "LogicException",
                        "Constant {me}:{0} does not match value {1}.",
                        $name,
                        $value
                    );
                }
            }

            self::$consts[$me] = $constants;
        }

        return self::$consts[$me];
    }