@Override
    public void getConfig(ApplicationIdConfig.Builder builder) {
        builder.tenant(applicationId.tenant().value());
        builder.application(applicationId.application().value());
        builder.instance(applicationId.instance().value());
    }
Prepares the model for start. The {@link VespaModel} calls
this methods after it has loaded this and all plugins have been loaded and
their initialize() methods have been called.

@param plugins All initialized plugins of the vespa model.
config-model/src/main/java/com/yahoo/config/model/ApplicationConfigProducerRoot.java