code: @Test public void assertGetFailoverItems(){
    JobRegistry.getInstance().registerJob("test_job",jobScheduleController,regCenter);
    when(jobNodeStorage.getJobNodeChildrenKeys("sharding")).thenReturn(Arrays.asList("0","1","2"));
    when(jobNodeStorage.isJobNodeExisted("sharding/0/failover")).thenReturn(true);
    when(jobNodeStorage.isJobNodeExisted("sharding/1/failover")).thenReturn(true);
    when(jobNodeStorage.isJobNodeExisted("sharding/2/failover")).thenReturn(false);
    when(jobNodeStorage.getJobNodeDataDirectly("sharding/0/failover")).thenReturn("127.0.0.1@-@0");
    when(jobNodeStorage.getJobNodeDataDirectly("sharding/1/failover")).thenReturn("127.0.0.1@-@1");
    assertThat(failoverService.getFailoverItems("127.0.0.1@-@1"),is(Collections.singletonList(1)));
    verify(jobNodeStorage).getJobNodeChildrenKeys("sharding");
    verify(jobNodeStorage).isJobNodeExisted("sharding/0/failover");
    verify(jobNodeStorage).isJobNodeExisted("sharding/1/failover");
    verify(jobNodeStorage).getJobNodeDataDirectly("sharding/0/failover");
    verify(jobNodeStorage).getJobNodeDataDirectly("sharding/1/failover");
    JobRegistry.getInstance().shutdown("test_job");
  }
  