public ActionResult HeadMedia(string workspace, string collection, int? year,
   int? month, int? day, string path)
 {
   string contentType;
   string etag = AtomPubService.GetMediaEtag(Collection.Id.AddPath(year, month, day, path),
     out contentType);
   HttpResult result = new HttpResult() { ContentType = contentType };
   result.Headers["ETag"] = etag;
   return result;
 }
 public ActionResult HeadEntry(string workspace, string collection, int? year,
   int? month, int? day, string path)
 {
   string etag = AtomPubService.GetEntryEtag(
     Collection.Id.AddPath(year, month, day, path));
   HttpResult result = new HttpResult() { ContentType = Atom.ContentTypeEntry };
   result.Headers["ETag"] = etag;
   return result;
 }