protected static void parseBridges(SiteConfig site_config, Node root) throws Exception {
        NodeList children=root.getChildNodes();
        if(children == null || children.getLength() == 0)
            return;
        for(int i=0; i < children.getLength(); i++) {
            Node node=children.item(i);
            if(node.getNodeType() != Node.ELEMENT_NODE)
                continue;
            String node_name=node.getNodeName();
            match(BRIDGE, node_name, true);

            NamedNodeMap attrs=node.getAttributes();
            if(attrs == null || attrs.getLength() == 0)
                continue;
            Attr name_attr=(Attr)attrs.getNamedItem("name");
            Attr config_attr=(Attr)attrs.getNamedItem("config");
            String name=name_attr != null? name_attr.getValue() : null;
            String config=config_attr.getValue();
            BridgeConfig bridge_config=new PropertiesBridgeConfig(name, config);
            site_config.addBridge(bridge_config);
        }
    }