@Override
    public void update(DiskEntry entry) {
      if (pendingKrfTags != null && entry.getVersionStamp() != null) {
        // Remember the version tag of the entry as it was written to the crf.
        pendingKrfTags.put(entry, new CompactVersionHolder(entry.getVersionStamp()));
      }
    }
A map of DiskEntry to the VersionTag that is written to disk associated with this tag. Only
needed for async regions so that we can generate a krf with a version tag that matches the
the tag we have written to disk for this oplog.
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java