struct LoginApi: Requestable {
    var userName: String = ""
    var passWord: String = ""

    var url: URLConvertible {
        return "https://host/to/path"
    }

    var method: HTTPMethod {
        return .POST
    }

    var var bodies: HTTPBodies {
        return [
            "user": userName,
            "pass": passWord
        ]
    }

    var headers: HTTPHeaders {
        return [:]
    }
}

let loginRequest = LoginApi().action()

loginRequest.responseJSON {
    debugPrint($0.result)
}

loginRequest.responseJSON(queue: DispatchQueue.global()) {
    debugPrint($0.result)
}
.responseString {
    switch $0.result {
    case .success(let value):
        debugPrint(value)
    case .failure(let error):
         debugPrint(error)
    }
}
// .cancel()