@Override
    public synchronized void shutdown() {
        super.shutdown();
        LOG.info("[FakePlacementDriverClient] shutdown successfully.");
    }
Single raft group, no need for a real PD role.

@author jiachun.fjc
jraft-rheakv/rheakv-core/src/main/java/com/alipay/sofa/jraft/rhea/client/pd/FakePlacementDriverClient.java