static DialogIO talkToMainProgram(S progID) {
  for (DialogIO io : talkToAllVMs()) {
    bool close = true;
    try {
      S pID = io.ask("what is the main program id?");
      if (sameSnippetID(pID, progID)) {
        close = false;
        ret io;
      }
    } finally {
      if (close)
        io.close();
    }
  }
  null;
}