public async Task <IFile> GetFile(string path)
        {
            var dbpath = new DBPath(path);

            var fileInfo = await filesystem.FileInfoForPathAsync(dbpath);

            return(new DropboxFile(fileInfo, filesystem));
        }
        public async Task WriteString(string contents)
        {
            await fileLock.WaitAsync();

            try {
                var file = await fileSystem.OpenFileAsync(fileInfo.Path);

                await file.WriteStringAsync(contents);

                file.Close();
                fileInfo = await fileSystem.FileInfoForPathAsync(fileInfo.Path);
            }
            finally {
                fileLock.Release();
            }
        }