private static function createObject($className, array $args = null)
    {
        try {
            if (!$args) {
                return new $className;
            } else {
                $c = new \ReflectionClass($className);
                return $c->newInstanceArgs($args);
            }
        } catch (\Exception $e) {
            throw new RuntimeException($e->getMessage(), $e->getCode(), $e);
        }
    }