public CSSkeleton(World world) {
   super(world);
   NMS.clearGoals(targetSelector, goalSelector);
   this.goalSelector.a(8, new PathfinderGoalLookAtPlayer(this, EntityHuman.class, 8.0F));
   getBukkitEntity()
       .setMetadata("noBurn", new FixedMetadataValue(KingdomDefense.getInstance(), true));
 }
  @Override
  protected Button[] setUp() {
    Button[] buttons = new Button[27];
    buttons = pane(buttons);
    if (structure instanceof Guardian) {
      ItemStack upgrade =
          new ItemBuilder(new ItemStack(Material.EMERALD_BLOCK))
              .name(ChatColor.YELLOW.toString() + ChatColor.BOLD + "Upgrade")
              .lore(
                  " ",
                  ChatColor.GREEN.toString()
                      + ChatColor.BOLD
                      + "Click to Upgrade to "
                      + (structure.getLevel() + 1),
                  ChatColor.RED + "Cost: " + structure.getNextCost())
              .build();
      Guardian structure = (Guardian) this.structure;
      if (structure.getLevel() == 4) {
        upgrade =
            new ItemBuilder(new ItemStack(Material.EMERALD_BLOCK))
                .name(ChatColor.AQUA.toString() + ChatColor.BOLD + "Fully Upgraded")
                .build();
      }
      ItemBuilder builder = new ItemBuilder(new ItemStack(Material.EMERALD));
      builder.name(ChatColor.GOLD + "Healing Cooldown");
      builder.lore(
          ChatColor.GREEN.toString()
              + structure.getCooldown()
              + " "
              + Utils.plural("second", structure.getCooldown()),
          ChatColor.GRAY
              + "Next: "
              + ChatColor.GREEN.toString()
              + (structure.getCooldown() - 5)
              + Utils.plural("second", structure.getCooldown() - 5));
      ItemStack health =
          new ItemBuilder(new Wool(DyeColor.LIME).toItemStack())
              .amount(1)
              .name(ChatColor.GOLD + "Health Per Cycle")
              .lore(
                  ChatColor.GREEN.toString() + structure.getHealthPerTick() + " hearts",
                  ChatColor.GRAY
                      + "Next: "
                      + ChatColor.GREEN.toString()
                      + (structure.getHealthPerTick() * 1.5)
                      + "hearts")
              .build();
      buttons[11] = new Button(builder.build(), () -> {});
      buttons[13] = new Button(health, () -> {});
      buttons[17] =
          new Button(
              upgrade,
              player -> {
                PlayerInfo info = KingdomDefense.getInstance().getInfoManager().get(player);
                if (!info.hasEnough(structure.getNextCost())) {
                  player.closeInventory();
                  info.sendMessage(ChatColor.RED + "You cannot afford this!");
                  return;
                }
                if (!info.remove(structure.getNextCost())) {
                  player.closeInventory();
                  info.sendMessage(ChatColor.RED + "You cannot afford this!");
                  return;
                }
                player.closeInventory();
                player.playSound(player.getLocation(), Sound.LEVEL_UP, 1.0F, 1.0F);
                if (structure.getLevel() == 5) {
                  return;
                }
                structure.setCooldown(structure.getCooldown() - 5);
                structure.setHealthPerTick(structure.getHealthPerTick() * 1.5);
                structure.setLevel(structure.getLevel() + 1);
                info.sendMessage(structure.getName() + ChatColor.AQUA + " tower upgraded!.");
              });
      return buttons;
    }
    buttons = pane(buttons);
    DefenseStructure structure = (DefenseStructure) this.structure;
    ItemBuilder builder = new ItemBuilder(new ItemStack(Material.EMERALD));
    builder.name(ChatColor.GOLD + "Fire Rate");
    builder.lore(
        ChatColor.GREEN.toString() + structure.getFireRate() + " projectiles per second",
        ChatColor.GRAY
            + "Next: "
            + ChatColor.GREEN.toString()
            + (structure.getFireRate() * 2)
            + " projectiles per second");

    ItemStack damage =
        new ItemBuilder(new ItemStack(Material.ARROW))
            .name(ChatColor.GOLD + "Damage")
            .lore(
                ChatColor.GREEN.toString() + structure.getDamage() + " hearts",
                ChatColor.GRAY
                    + "Next: "
                    + ChatColor.GREEN
                    + (structure.getDamage() * 1.5)
                    + " hearts")
            .build();

    buttons[11] = new Button(builder.build(), () -> {});
    buttons[13] = new Button(damage, () -> {});

    ItemStack upgrade =
        new ItemBuilder(new ItemStack(Material.EMERALD_BLOCK))
            .name(ChatColor.YELLOW.toString() + ChatColor.BOLD + "Upgrade! ")
            .lore(
                " ",
                ChatColor.GREEN.toString()
                    + ChatColor.BOLD
                    + "Click to Upgrade to Level "
                    + (structure.getLevel() + 1),
                ChatColor.RED + "Cost: " + structure.getNextCost())
            .build();
    if (structure.getLevel() == 4) {
      upgrade =
          new ItemBuilder(new ItemStack(Material.EMERALD_BLOCK))
              .name(ChatColor.AQUA.toString() + ChatColor.BOLD + "Fully Upgraded")
              .build();
    }
    buttons[17] =
        new Button(
            upgrade,
            player -> {
              PlayerInfo info = KingdomDefense.getInstance().getInfoManager().get(player);
              if (!info.hasEnough(structure.getNextCost())) {
                player.closeInventory();
                info.sendMessage(ChatColor.RED + "You cannot afford this!");
                return;
              }
              if (!info.remove(structure.getNextCost())) {
                player.closeInventory();
                info.sendMessage(ChatColor.RED + "You cannot afford this!");
                return;
              }
              player.closeInventory();
              player.playSound(player.getLocation(), Sound.LEVEL_UP, 1.0F, 1.0F);
              if (structure.getLevel() == 5) {
                return;
              }
              structure.setFireRate(structure.getFireRate() * 2);
              structure.setDamage(structure.getDamage() * 1.5);
              structure.setLevel(structure.getLevel() + 1);
              player.closeInventory();
              info.sendMessage(structure.getName() + ChatColor.YELLOW + " tower upgraded!.");
            });
    return buttons;
  }