@NotNull
  public static ConcurrentBitSet readFrom(@NotNull File file) throws IOException {
    if (!file.exists()) {
      return ConcurrentBitSet.create();
    }
    try (DataInputStream bitSetStorage = new DataInputStream(new BufferedInputStream(new FileInputStream(file)))) {
      return ConcurrentBitSet.readFrom(bitSetStorage);
    }
  }
@NotNull
  public static ConcurrentBitSet readFrom(@NotNull File file)