private static void validateAdminV20Elements(DeployState deployState, ModelElement adminElement) {
        var validForVersion2Elements = List.of("adminserver", "cluster-controllers", "configservers", "logserver", "monitoring", "slobroks");
        var used = validForVersion2Elements.stream()
                                           .filter(e -> ! adminElement.children(e).isEmpty())
                                           .map(e -> "'" + e + "'")
                                           .collect(Collectors.joining(", "));
        if ( ! used.isEmpty())
            deployState.getDeployLogger().logApplicationPackage(WARNING, "Elements " + used + " in <admin> are deprecated and ignored, please remove");
    }
Returns the count first containers in the current model having isRetired set to the given value
config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV4Builder.java