public function calculateCartTotal(array $items): float 	{ 		$products = Product::select(['id', 'price_with_pdv'])->whereIn('id', array_keys($items))->get(); 		$total = 0;  		foreach ($items as $productId => $quantity) { 			$total += $products->firstWhere('id', $productId)->price_with_pdv * $quantity; 		}  		return $total; 	}