@Override
  public Region<?, ?> getRegion() {
    // The region will be null mostly for the other node where the gateway event
    // is serialized
    return region != null ? region
        : CacheFactory.getAnyInstance().getRegion(regionPath);
  }
Return the EventSequenceID of the Event
geode-core/src/main/java/org/apache/geode/internal/cache/wan/GatewaySenderEventImpl.java