public Task<EntityVersion<WebResourceName, string>> TryUpdateEntity(WebResourceName url, string etag, string iCalData) { var path = Path.Combine(_directory.FullName, url.OriginalAbsolutePath); File.WriteAllText(path, iCalData); return Task.FromResult(EntityVersion.Create(url, File.GetLastWriteTimeUtc(path).ToString("o"))); } }