@Override
    protected void doBuildAdmin(DeployState deployState, Admin admin, Element w3cAdminElement) {
        ModelElement adminElement = new ModelElement(w3cAdminElement);
        admin.addConfigservers(getConfigServersFromSpec(deployState, admin));

        // Note: These two elements only exists in admin version 4.0
        // This build handles admin version 3.0 by ignoring its content (as the content is not useful)
        Optional<NodesSpecification> requestedSlobroks = 
                NodesSpecification.optionalDedicatedFromParent(adminElement.child("slobroks"), context);
        Optional<NodesSpecification> requestedLogservers = 
                NodesSpecification.optionalDedicatedFromParent(adminElement.child("logservers"), context);

        assignSlobroks(deployState, requestedSlobroks.orElse(NodesSpecification.nonDedicated(3, context)), admin);
        assignLogserver(deployState, requestedLogservers.orElse(createNodesSpecificationForLogserver()), admin);

        addLogForwarders(adminElement.child("logforwarding"), admin, deployState);
        addLoggingSpecs(adminElement.child("logging"), admin);

        validateAdminV20Elements(deployState, adminElement);
    }
Builds the admin model from a version 4 XML tag, or as a default when an admin 3 tag or no admin tag is used.

@author bratseth
config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/DomAdminV4Builder.java