.verifyByZkCallback(new ClusterStateVerifier.BestPossAndExtViewZkVerifier(_zkaddr,
clusterName));
Assert.assertTrue(result);
// stop controller, redefine state model definition, and re-start controller
controller.syncStop();
redefineStateModelDef(clusterName);
controller = new MockController(_zkaddr, clusterName, "controller_0");
controller.syncStart();
result =