public static function toString($error)
    {
        if (is_int($error) && in_array($error, self::$errors)) {
            $error = array_search($error, self::$errors);
        }
        if (!is_string($error) || !isset(self::$errors[$error])) {
            self::toss(
                "InvalidArgument",
                "The value {0} is not a valid E_ERROR constant value.",
                $error
            );
        }
        
        return $error;
    }