How to use

getDisplay

method

in

net.minecraft.advancements.Advancement

@SubscribeEvent
public void onAchievement(AdvancementEvent event) {
 final @Nonnull Advancement advancement = NullHelper.notnullF(event.getAdvancement(), "AdvancementEvent.getAdvancement()");
 DisplayInfo display = advancement.getDisplay();
 if (ConfigHandler.betterAchievements && !event.getEntity().world.isRemote && display != null && display.shouldAnnounceToChat()) {
  event.getEntityPlayer().getEntityData().setInteger("fireworksLeft", 9);
  event.getEntityPlayer().getEntityData().setBoolean("fireworkDelay", false);
 }
}