@Override
    public void toData(DataOutput out,
        SerializationContext context) throws IOException {
      super.toData(out, context);
      DataSerializer.writeObject(eventId, out);
      DataSerializer.writeObject(key, out);

      DistributedRegion region = (DistributedRegion) event.getRegion();
      if (region instanceof BucketRegion) {
        PartitionedRegion pr = region.getPartitionedRegion();
        if (pr.isParallelWanEnabled()) {
          DataSerializer.writeBoolean(Boolean.TRUE, out);
          DataSerializer.writeLong(event.getTailKey(), out);
        } else {
          DataSerializer.writeBoolean(Boolean.FALSE, out);
        }
      } else if (region.isUsedForSerialGatewaySenderQueue()) {
        DataSerializer.writeBoolean(Boolean.TRUE, out);
        DataSerializer.writeLong(event.getTailKey(), out);
      } else {
        DataSerializer.writeBoolean(Boolean.FALSE, out);
      }
    }
This operation updates Version stamp of an entry if entry is available and entry version stamp
has same DSID as in event's version tag.
geode-core/src/main/java/org/apache/geode/internal/cache/UpdateEntryVersionOperation.java