@Test(expected = IllegalArgumentException.class)
  public void testCreateClusterWithInvalidRequest4() throws Exception {
    ClusterRequest r = new ClusterRequest(null, null, State.INSTALLING.name(), null, "HDP-1.2.0", null);
    controller.createCluster(r);
    controller.updateClusters(Collections.singleton(r), null);
  }
Allows to set maintenanceStateHelper. For use when there is anything to test
with maintenance mode.
ambari-server/src/test/java/org/apache/ambari/server/controller/AmbariManagementControllerTest.java