@Test
    void testSeparateHostsFromConfigServerRequired() {
        assertThrows(IllegalArgumentException.class, () -> {
            String xml = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n" +
                    "<services>\n" +
                    "\n" +
                    "  <admin version=\"2.0\">\n" +
                    "    <adminserver hostalias=\"mockhost\" />\n" +
                    "    <configservers>\n" +
                    "      <configserver hostalias=\"mockhost\" />" +
                    "    </configservers>" +
                    "    <cluster-controllers standalone-zookeeper=\"true\">\n" +
                    "      <cluster-controller hostalias=\"mockhost\"/>" +
                    "    </cluster-controllers>\n" +
                    "  </admin>\n" +
                    "  <content version='1.0' id='bar'>" +
                    "     <redundancy>1</redundancy>\n" +
                    "     <documents>" +
                    "     </documents>\n" +
                    "     <group>" +
                    "       <node hostalias='mockhost' distribution-key='0' />" +
                    "     </group>" +
                    "   </content>" +
                    "\n" +
                    "</services>";
            TestDriver driver = new TestDriver();
            driver.buildModel(xml);
        });
    }
Test for creating cluster controllers under the admin tag.
config-model/src/test/java/com/yahoo/vespa/model/admin/ClusterControllerTestCase.java