public function getNumberOfPackagesForFreeShipping(float|string $weight): ShippingReturnObject 	{ 		$numberOfPackages = 0;  		while ($weight > self::SINGLE_SHIPMENT_MAX_WEIGHT) { 			$numberOfPackages++;  			$weight = $weight - self::SINGLE_SHIPMENT_MAX_WEIGHT; 		}  		$numberOfPackages++;  		return new ShippingReturnObject($numberOfPackages, '0', 'Free shipping'); 	}