Moya: How/where to set the HTTP JSON body, Error: Response: Received empty network response for

my moya config

public var method: Moya.Method {
    switch self {
    case .uploadPictureTest:
        return .GET
    case .register:
        return .POST
    case .login:
        return .POST
    }
}

public var parameterEncoding: Moya.ParameterEncoding {
    switch self {
    case .register:
        return ParameterEncoding.JSON
    default:
        return ParameterEncoding.Custom(MyAPICallCustomEncodingClosure)
    }
}

get this errror

Moya_Logger: [11/09/2016 15:53:17] Request: <NSMutableURLRequest: 0x7f801492de90> { URL: http://test.fragment.com.cn/rest/phone_register/new }
Moya_Logger: [11/09/2016 15:53:17] Request Headers: ["X-ApiKey": "xxx", "Content-Type": "application/json"]
Moya_Logger: [11/09/2016 15:53:17] HTTP Request Method: POST
Moya_Logger: [11/09/2016 15:53:17] Request Body: {"country_code":"86","phone":18815289863}
Moya_Logger: [11/09/2016 15:53:17] Response: Received empty network response for register("86", 18815289863).

How to solve this problem, thanks