@Override
    public Boolean call() {
      try {
        ZKPropertyStore<ZNRecord> store =
            new ZKPropertyStore<ZNRecord>(
                new ZkClient(ZK_ADDR), new PropertyJsonSerializer<ZNRecord>(ZNRecord.class), _root);

        store.setProperty("key2", _record);
        store.updatePropertyUntilSucceed("key2", new TestUpdater());

        return Boolean.TRUE;
      } catch (Exception e) {
        LOG.error(e);
        return Boolean.FALSE;
      }
    }