dynamic sendRequest(String remoteFileName, String method, XFile file, int length) async {
    final uri = Uri(path: baseURL + '/' + nameOfZone + '/' + Uri.encodeFull(remoteFileName));
    final req = http.MultipartRequest(method, uri);

    var s = await file.readAsBytes();
    String baseName = basename(file.path);

    final multipartFile = http.MultipartFile('picture', http.ByteStream.fromBytes(s), length, filename: baseName);

    req.files.add(multipartFile);

    req.fields['User-Agent'] = 'Java-BCDN-Client-' + version;
    req.fields['AccessKey'] = apiKey;
    req.fields['Content-Type'] = 'application/octet-stream';

    switch (method) {
      case "PUT":
        final res = await req.send();
        await for (var value in res.stream.transform(utf8.decoder)) {
          debugPrint(value);
        }
        break;
    }
  }