public ShopItem[] getItemsByID(int... ids) {
		Set<ShopItem> cache = new HashSet<>();
		if (ids != null && ids.length > 0)
			for (ShopItem nextItem : items)
				for (int nextID : ids)
					if (nextItem.getID() == nextID)
						cache.add(nextItem);
		return cache.isEmpty() ? null : cache.toArray(new ShopItem[cache.size()]);
	}