public function updateShipmentOrder($shipmentNumber) {
		if(is_array($shipmentNumber) || $this->countShipmentOrders() > 1) {
			$this->addError(__FUNCTION__ . ': Updating Shipments is a Single-Operation only!');

			return false;
		}

		switch($this->getMayor()) {
			case 1:
				$data = null;
				break;
			case 2:
			default:
				if($this->countShipmentOrders() < 1)
					$data = $this->createShipmentClass_v2_legacy($shipmentNumber);
				else
					$data = $this->createShipmentClass_v2($shipmentNumber);
		}

		$response = null;

		// Create Shipment
		try {
			$response = $this->sendUpdateRequest($data);
		} catch(Exception $e) {
			$this->addError($e->getMessage());

			return false;
		}

		if(is_soap_fault($response)) {
			$this->addError($response->faultstring);

			return false;
		} else
			return new Response($this->getVersion(), $response);
	}