@Override
  public Map<ThreadIdentifier, EventSequenceNumberHolder> getState() {
    Map<ThreadIdentifier, EventSequenceNumberHolder> result = new HashMap<>(recordedEvents.size());
    for (Map.Entry<ThreadIdentifier, EventSequenceNumberHolder> entry : recordedEvents.entrySet()) {
      EventSequenceNumberHolder holder = entry.getValue();
      // don't transfer version tags - adds too much bulk just so we can do client tag recovery
      result.put(entry.getKey(),
          new EventSequenceNumberHolder(holder.getLastSequenceNumber(), null));
    }
    return result;
  }
Create an event tracker

@param region the region
geode-core/src/main/java/org/apache/geode/internal/cache/event/DistributedEventTracker.java