private RTSGroup latestRTSG() {
        RTSGroup latest = null;
        for (RTSGroup rtsg : rtsGroups.values()) {
            latest = latest == null ? rtsg : rtsg.createTime() > latest.createTime() ? rtsg : latest;
        }
        return latest;
    }
Close this realtime table. Job is done.
This method only called before process exit.
indexr-segment/src/main/java/io/indexr/segment/rt/RealtimeTable.java