private void migrateLastPushedSeqIds(ZKReplicationQueueStorageForMigration oldQueueStorage)
    throws Exception {
    MigrationIterator<List<ZkLastPushedSeqId>> iter = oldQueueStorage.listAllLastPushedSeqIds();
    for (;;) {
      List<ZkLastPushedSeqId> list = iter.next();
      if (list == null) {
        return;
      }
      queueStorage.batchUpdateLastSequenceIds(list.stream()
        .filter(data -> peers.containsKey(data.getPeerId())).collect(Collectors.toList()));
    }
  }
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