public function alert($channelNames, $message, $tos = ['@dee'])
  {

    $to = implode(',', $tos);
    foreach ($channelNames as $channelName) {
      $channelKey = $this->lookupChannelKey($channelName);
      $slack = new Client($channelKey);
      $slack->to($to)->attach($message)->send();
      $this->statHat->ezCount('MB_Toolbox: MB_Slack: alert', 1);
    }
  }