i need help

package net.mcreator.amulets.procedures;

/* imports omitted */

public class RegenerationProcedure {
	public static void execute(LevelAccessor world, Entity entity, ItemStack itemstack) {
		if (entity == null)
			return;
		double ifItemOnCooldown = 0;
		if (ifItemOnCooldown == 0) {
			ifItemOnCooldown = 1;
			if (entity instanceof Player _player)
				_player.getCooldowns().addCooldown(itemstack.getItem(), 400);
			if (entity instanceof LivingEntity _entity)
				_entity.addEffect(new MobEffectInstance(MobEffects.HEAL, 1, 1, (false), (false)));
			new Object() {
				private int ticks = 0;
				private float waitTicks;
				private LevelAccessor world;

				public void start(LevelAccessor world, int waitTicks) {
					this.waitTicks = waitTicks;
					MinecraftForge.EVENT_BUS.register(this);
					this.world = world;
				}

				@SubscribeEvent
				public void tick(TickEvent.ServerTickEvent event) {
					if (event.phase == TickEvent.Phase.END) {
						this.ticks += 1;
						if (this.ticks >= this.waitTicks)
							run();
					}
				}

				private void run() {
					MinecraftForge.EVENT_BUS.unregister(this);
				}
			}.start(world, 400);
		}
	}
}