public static function fromClassname($class)
    {
        try {
            if (!class_exists($class)) {
                throw new InvalidArgumentException(sprintf('The class "%s" does not exist', $class));
            }

            return new self(ClassUtils::getRealClass($class), 'class');
        } catch (InvalidArgumentException $e) {
            throw new InvalidSubjectIdentityException($e->getMessage(), 0, $e);
        }
    }