svoid restoreLatestBackupIfConceptsFileEmpty(S dbID, O... _) {
  bool doIt = boolPar doIt(_);
  File file = conceptsFile(dbID);
  if (fileExists(file) && fileSize(file) == 0) {
    print(file + " corrupted, trying to restore");
    File backup = lastThat fileNotEmpty(sortByFileName(conceptBackupFiles(dbID)));
    if (backup == null) ret with print("No usable backup found :(");
    S msg = "RESTORING: " + backup;
    File log = javaxDataDir("db-restores.log");
    if (doIt) logQuotedWithTime(log, msg);
    print(stringIf(!doIt, "[would be] ") + msg);
    if (doIt) {
      clearConceptsOf(dbID);
      copyFile(backup, file);
      print(msg = "DB RESTORED!");
      if (doIt) logQuotedWithTime(log, msg);
    }
  }
}