@Override
    Element servicesXml() {
        return parse(
            "<search>",
            "  <searcher id='searcher:1' classId='classId1' />",

            "  <provider id='provider:1' inherits='parentChain1 parentChain2' excludes='ExcludedSearcher1 ExcludedSearcher2'",
            "             cacheweight='2.3'>",
            "    <federationoptions optional='true' timeout='2.3 s' />",
            "    <nodes>",
            "      <node host='sourcehost1' port='12'/>",
            "      <node host='sourcehost2' port='34'/>",
            "    </nodes>",

            "    <source id='source:1' inherits='parentChain3 parentChain4' excludes='ExcludedSearcher3 ExcludedSearcher4'>",
            "      <federationoptions timeout='12 ms' />",
            "    </source>",
            "    <source id='source:2' />",
            "  </provider>",

            "  <provider id='provider:2' type='local' cluster='cluster1' />",
            "  <provider id='provider:3' />",

            "  <provider id='vespa-provider'>",
            "    <nodes>",
            "      <node host='localhost' port='" + Defaults.getDefaults().vespaWebServicePort() + "' />",
            "   </nodes>",
            "     <config name='search.federation.provider'>",
            "       <queryType>PROGRAMMATIC</queryType>",
            "    </config>",
            "  </provider>",
            "</search>");
    }
Test of search chains config
<p>TODO: examine the actual values in the configs.</p>

@author Tony Vaagenes
config-model/src/test/java/com/yahoo/vespa/model/container/search/searchchain/SchemaChainsTest.java