pocketmine\event\player\PlayerQuitEvent::getQuitMessage PHP Method

    public function getQuitMessage()
    {
        return $this->quitMessage;
    }

 public function onPlayerQuitEvent(PlayerQuitEvent $event)
 {
     $message = $event->getQuitMessage();
     if ($message instanceof TranslationContainer) {
         $message = $this->getServer()->getLanguage()->translateString($message->getText(), $message->getParameters());
     }
     AnnounceSystem::getInstance()->pushBroadCastPopup($message, 2);
     $event->setQuitMessage(null);
 }