void OnTriggerEnter2D(Collider2D collider)
    {
        ItemObject itemObject = collider.GetComponent <ItemObject>();

        if (itemObject != null && !itemObject.pickedUp)
        {
            SoundEffectManager.Instance.PlayItemCollect();

            itemObject.pickedUp = true;

            itemObject.AddItemInstance(itemHolder.gameObject);
            PutItemObjectAway(itemObject.gameObject);

            string itemName = itemObject.itemToSpawn;
            Item   item     = itemHolder.gameObject.GetComponent(itemName) as Item;
            //Debug.Log(item.ItemName);
            CollectItem(item);
        }
    }