我似乎无法从 OpenSky-network 创建数据字符串

Question

我做错了什么？我正在尝试创建一个 URLSession 以将数据从 OpenSky 下载到数据字符串中。我有 2 个打印语句用于调试。

   let skyURL = "https://opensky-network.org/api/states/all?lamin=35&lomin=-114&lamax=37&lomax=-112"

func performSkyRequest(urlString: String){
    
    if let url = URL(string: urlString){
        let session = URLSession(configuration: .default)
        let task = session.dataTask(with: url) { (data, response, error) in
            if error != nil {
                print(error!)
                return
            }
            if let safeData = data {
                let dataString = String(data: safeData, encoding: .utf8)
                print(safeData)
                print(dataString)
            }
        }
   
        task.resume
    }
}
performSkyRequest(urlString: skyURL)