protected bool IsSimulatedFileUrl(string localPath)
{
var extension = Path.GetExtension(localPath);
if(extension != null && !extension.StartsWith(".htm"))
return false;
// a good improvement might be to make these urls more obviously cache requests. But for now, let's just see if they are filename guids
var filename = Path.GetFileNameWithoutExtension(localPath);
Guid result;
return Guid.TryParse(filename, out result);
}