private static void addServices(ApplicationSpec app, Element element) {
        String protocol = element.getAttribute("protocol");
        for (Element node : XML.getChildren(element, "service")) {
            app.addService(protocol, node.getAttribute("name"));
        }
    }
This function updates the given application with the data contained in the given xml element.

@param app The application to update.
@param element The element to base the services on.
config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomRoutingBuilder.java