code: public void markAllNewWorkers(Map<Integer, String> workerIds) {
          int startTime = TimeUtils.current_time_secs();
  
          for (Entry<Integer, String> entry : workerIds.entrySet()) {
              String oldWorkerIds = portToWorkerId.get(entry.getKey());
              if (oldWorkerIds != null) {
                  workerIdToStartTimeAndPort.remove(oldWorkerIds);
                  // update portToWorkerId
                  LOG.info("A port is still occupied by an old worker, remove useless "
                          + oldWorkerIds + " from workerIdToStartTimeAndPort");
              }
              portToWorkerId.put(entry.getKey(), entry.getValue());
              workerIdToStartTimeAndPort.put(entry.getValue(), new Pair<>(startTime, entry.getKey()));
          }
      }
docs: mark all new Workers like 52b11418-7474-446d-bff5-0ecd68f4954f