public function cartItems(CartItems $request): JsonResource 	{ 		$items = $request->items; 		$products = array_column($items, 'product_id'); 		$variants = array_column($items, 'variant_id');  		return ProductSingleResource::collection(Product::includes($request->lang)->with(['variants' => function ($query) use ($variants) { 			$query->whereIn('id', $variants); 		}])->available()->whereIn('id', $products)->get()); 	}