protected void fillVersionedObjectList(VersionedObjectList list) {
    for (PutAllEntryData entry : putAllData) {
      if (entry.versionTag != null) {
        list.addKeyAndVersion(entry.key, entry.versionTag);
      }
    }
  }
version tags are gathered from local operations and remote operation responses. This method
gathers all of them and stores them in the given list.
geode-core/src/main/java/org/apache/geode/internal/cache/DistributedPutAllOperation.java