static S sendToBotQuietly(int port, S text, O... args) {
  ret sendToBotQuietly(String.valueOf(port), text, args);
}

static S sendToBotQuietly(S bot, S text, O... args) {
  text = format3(text, args);
  
  temp DialogIO channel = findBot(bot);
  if (channel == null)
    fail(quote(bot) + " not found");
  try {
    channel.readLine();
    channel.sendLine(text);
    return channel.readLine();
  } catch (Throwable e) {
    e.printStackTrace();
    return null;
  }
}