protected function buildClass($name)
    {
        $className = $this->formatClassName($name);

        if (!class_exists($className)) {
            throw new RuntimeException('Enum '.$className.' is not exists');
        }

        $enum = new $className();
        if (!$enum instanceof Enumable) {
            throw new RuntimeException('Enum '.$className.' is not instance of '.Enumable::class);
        }

        return $enum;
    }