@Override
  public void onConfigurationChange(Configuration conf) {
    this.conf = conf;
    this.peerStorage = ReplicationStorageFactory.getReplicationPeerStorage(fs, zk, conf);
  }
For replication peer cluster key or endpoint class, null and empty string is same. So here
don't use {@link StringUtils#equals(CharSequence, CharSequence)} directly.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/replication/ReplicationPeerManager.java