private void AddDocumentToFolder(Folder folder, string document, string[] subfolders) { if (subfolders == null || subfolders.Length == 0) { folder.Add(document); return; } if (subfolders[0].EndsWith(":")) { return; } var folderName = Paths.SanitizeFolder(subfolders[0]); Folder subfolder = folder.GetOrCreateFolder(folderName); AddDocumentToFolder(subfolder, document, subfolders.Skip(1).ToArray()); }