private static byte @NotNull [] readHashBytesFromFile(@NotNull File file) throws IOException {
    try (FileInputStream stream = doIOOperation(lastAttempt -> {
      try {
        return new FileInputStream(file);
      }
      catch (FileNotFoundException e) {
        if (lastAttempt) throw e;
        return null;
      }
    })) {
      return FileUtil.loadBytes(Objects.requireNonNull(stream), 20);
    }
  }
private static byte @NotNull [] readHashBytesFromFile(@NotNull File file)