public sealed class WebClientFileDownloader : IFileDownloader
    {
        private NetworkCredential _networkCredentials;
        public string UserName => _networkCredentials.UserName;
        public string Password => _networkCredentials.Password;
        public string Host { get; private set; }

        public WebClientFileDownloader(string host, string userName = null, string password = null)
        {
            _networkCredentials = new NetworkCredential(userName, password);
            Host = host;
        }

        public async Task DownloadFileAsync(FullFileInfo fullFileInfo, CancellationToken cancellationToken, IProgress<double> progress)
        {
            Task downloadingTask = DownloadFileAsync(fullFileInfo.LocalFileInfo, fullFileInfo.FtpFileInfo, cancellationToken, progress);
            await Task.WhenAny(downloadingTask, Task.Delay(int.MaxValue, cancellationToken));
        }

        private async Task DownloadFileAsync(FileInfo localFileInfo, FtpFileInfo ftpFileInfo, CancellationToken cancellationToken, IProgress<double> progress)
        {
            FileInfo tempLocalFile = new FileInfo(localFileInfo.FullName + "_temp" + DateTime.UtcNow.Ticks);
            Debug.Log(tempLocalFile.FullName);

            try
            {
                using (WebClient client = new WebClient() { Credentials = _networkCredentials })
                using (cancellationToken.Register(() =>
                {
                    Debug.Log("Отменю текущую загрузку");
                    client.CancelAsync();
                    Debug.Log("Отменил текущую загрузку");
                }))
                {
                    client.DownloadProgressChanged += (s, e) =>
                        progress.Report(e.BytesReceived / (double)ftpFileInfo.Size * 100D);

                    Uri url = new Uri(new Uri("ftp://" + Host), ftpFileInfo.FullName);
                    await client.DownloadFileTaskAsync(url, tempLocalFile.FullName);
                    tempLocalFile.MoveTo(localFileInfo.FullName);
                }
            }
            catch (Exception exc)
            {
                Debug.LogException(exc);
                tempLocalFile.DeleteIfExists();
            }
            Debug.Log("Выхожу из метода загрузки");
        }