in Core/src/Impl/Storages/FileSystemStorage.cs [241:253]
private void TryRemoveEmptyDirsToRootDir(string dir)
{
Debug.Assert(myRwLock.IsWriteLockHeld);
while (!string.IsNullOrEmpty(dir))
{
var fullDir = Path.Combine(myRootDir, dir);
if (Directory.EnumerateFileSystemEntries(fullDir).Any())
return;
Directory.Delete(fullDir);
dir = Path.GetDirectoryName(dir) ?? "";
}
}