private void initVersionsBytes(DiskEntry entry) throws IOException {
      // persist entry version, region version and memberId
      // The versions in entry are initialized to 0. So we will not persist the
      // 3
      // types of data if region version is 0.

      // TODO: This method will be called 2 times, one for persisting into crf
      // another for persisting into krf, since we did not save the byte arrary
      // for the verstion tag.
      VersionStamp stamp = entry.getVersionStamp();
      if (EntryBits.isWithVersions(userBits)) {
        assert (stamp != null);
        versionsBytes = serializeVersionTag(stamp);
        size += versionsBytes.length;
      }
    }
How many bytes it will be when serialized
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java