class Connection: NSObject, URLSessionDataDelegate {

    lazy var session: URLSession = {
        URLSession(configuration: URLSessionConfiguration.default, delegate: self, delegateQueue: nil)
    }()

    func start() {
        let baseURL = ""
        let keyID = ""
        let url = URL(string: "\(baseURL)/v2/path/\(keyID)")!

        var urlRequest = URLRequest(url: url)
        urlRequest.setValue("application/x-ndjson", forHTTPHeaderField: "Accept")
        let tasks = session.dataTask(with: urlRequest)
        tasks.resume()
    }

    func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
        print("ReceivedData: \(data) - \(String(data: data, encoding: .utf8))") //But since it's chunk, the conversion to String might fail
    }

    func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
        print("didComplete withError: \(error)")
    }
}