@EventHandler(priority = EventPriority.NORMAL)
    public void onExpBottleEvent (ExpBottleEvent event)
      {
        for (MetadataValue meta : event.getEntity().getMetadata(
            "expbottlelevel"))
          {
            if (meta == null)
              return;
            if (meta.getOwningPlugin() != plugin)
              continue;
            event.setExperience(event.getExperience() * meta.asInt());
            break;
          }
      }