Thruway\Role\Broker::handleSendWelcomeMessage PHP Method

    public function handleSendWelcomeMessage(MessageEvent $event)
    {
        /** @var WelcomeMessage $welcomeMessage */
        $welcomeMessage = $event->message;
        //Tell the welcome message what features we support
        $welcomeMessage->addFeatures('broker', $this->getFeatures());
    }