@BeforeEach
    public void setupSearchChains() {
        SearchChains searchChains = new DomSearchChainsBuilder().build(root.getDeployState(), root, servicesXml());
        searchChains.initialize(MockSearchClusters.twoMockClusterSpecsByName(root));
        root.freezeModelTopology();
    }
Creates SearchChains model from xml input.
@author Tony Vaagenes
config-model/src/test/java/com/yahoo/vespa/model/container/search/searchchain/SchemaChainsTestBase.java