public function getServerNodeConfiguration(ServerNodeInterface $serverNode)
    {

        // query whether a server signature (software) has been configured
        if ($serverNode->getParam('software') == null) {
            $serverNode->setParam('software', ParamNode::TYPE_STRING, $this->getService()->getServerSignature());
        }

        // add the server node configuration
        return new ServerNodeConfiguration($serverNode);
    }