@Override
        public void doBuild(ContainerModelAmender model, Element spec, ConfigModelContext modelContext) {
            if (built) return; // the same instance will be called once per container cluster
            for (ContainerModel containerModel : model.containerModels)
                amend(containerModel.getCluster());
            built = true;
        }
Depend on all models adding hosts to the system as this this should amend services on all hosts
config-model/src/test/java/com/yahoo/vespa/model/test/ModelAmendingTestCase.java