svoid restoreConceptsBackup(S dbID, File backup, bool doIt) {
  File file = conceptsFile(dbID);
  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);
  }
}