@Override
  public boolean isDirtyStamp(Stamp stamp, File file, @NotNull BasicFileAttributes attrs) throws IOException {
    if (!(stamp instanceof HashStamp)) return true;
    HashStamp filesStamp = (HashStamp)stamp;
    if (!myTimestampStorage.isDirtyStamp(FileTimestamp.fromLong(filesStamp.myTimestamp), file, attrs)) return false;
    Long hash = filesStamp.myHash;
    if (hash == null) return true;
    return hash != getFileHash(file);
  }
@Override
  public boolean isDirtyStamp(Stamp stamp, File file, @NotNull BasicFileAttributes attrs)