static L<FirefoxTab> firefoxTabs() {
  File profile = mozillaDefaultProfileDir();
  if (profile == null) null; // print("No default Mozilla profile found");
  Map data = cast decodeMozillaJSONLZ4File(newFile(profile, "sessionstore-backups/recovery.jsonlz4"));
  if (data == null) null; // print("No session found");
  int iWindow = 0;
  new L<FirefoxTab> out;
  for (Map window : unnull((L<Map>) data.get("windows"))) {
    ++iWindow;
    for (Map tab : unnull((L<Map>) window.get("tabs"))) {
      int index = toInt(tab.get("index"))-1;
      L<Map> entries = cast tab.get("entries");
      Map entry = entries.get(index);
      S title = cast entry.get("title");
      S url = cast entry.get("url");
      out.add(FirefoxTab(iWindow, title, url));
    }
  }
  ret out;
}