如何将URLRequest转换为Alamofire.URLConvertible

Question

如何将URLRequest转换为Alamofire URLConvertible我尝试转换以下代码时遇到错误

var request = URLRequest(url: URL(string: "some url")!)
request.httpBody = json
RxAlamofire.request(.post, request as! URLConvertible, parameters: param, encoding: JSONEncoding.default, headers: ["Content-Type" : "application/json"])
    .subscribe(onNext:{ [weak self] (json) in
        print(json)
        if let jsonResult = JSON(json) as? JSON {
            if let cartResult = FoodCartResult(jsonResult) as? FoodCartResult {
                self?.delegate?.showCart(cartresult: cartResult)
            }
        }

        }, onError: {
            [weak self] (error) in
            print(error.localizedDescription)
            self?.delegate?.onError()
        },onCompleted: {})
    .disposed(by: disposeBag)

代码使我的应用程序崩溃

  

无法将类型“ Foundation.URLRequest”（0x10c23a3c8）的值强制转换为“ Alamofire.URLConvertible”

已经推荐以下人，但不为我工作 Could not cast value of type 'NSMutableURLRequest' (0x11beb7040) to 'Alamofire.URLRequestConvertible' (0x11beb9040)