public async void Upload(string accessToken, string filename, byte[] content, Action onUploadSuccess)
        {
            _logger.Info("set access token");
            _dropbox.AccessToken = accessToken;

            _logger.Info("start uploading to dropbox");
            await _dropbox.Upload("", filename, content, onUploadSuccess);
        }
        //[TestMethod]
        public void UploadTest()
        {
            const string folder = "";
            const string file   = "test.sfs";

            byte[] content;
            using (FileStream fileStream = File.OpenRead("dropboxTest.sfs"))
            {
                content = new byte[fileStream.Length];

                fileStream.Read(content, 0, (int)fileStream.Length);
                fileStream.Close();
            }

            var  dropboxClient = new DropboxWrapper();
            Task task          = dropboxClient.Upload(folder, file, content, delegate {  });

            task.Wait();
        }