private void CleanupMismatchFolder(SnapshotFullName snapshotFullName) { if (!_mismatchFolders.Contains(snapshotFullName.FolderPath)) { lock (_lockObject) { if (!_mismatchFolders.Contains(snapshotFullName.FolderPath)) { _snapshotFileHandler.DeleteSnapshotSubfolder( snapshotFullName, FileNames.MismatchFolderName); _mismatchFolders.Add(snapshotFullName.FolderPath); } } } }