public function shopRates($rateRequest)
    {
        if ($rateRequest instanceof Shipment) {
            $shipment = $rateRequest;
            $rateRequest = new RateRequest();
            $rateRequest->setShipment($shipment);
        }

        $this->requestOption = 'Shop';

        return $this->sendRequest($rateRequest);
    }
public function shopRates($rateRequest)
    {
        if ($rateRequest instanceof Shipment) {
            $shipment = $rateRequest;
            $rateRequest = new RateRequest();
            $rateRequest->setShipment($shipment);
        }

        $this->requestOption = 'Shop';

        return $this->sendRequest($rateRequest);
    }
@param $rateRequest

@throws Exception

@return RateResponse