@Override
    public String toString() {
      return super.toString() + " batchedExpiredTombstones[" + expiredTombstones.size() + "] = "
          + expiredTombstones;
    }
Returns true if keys needs to be tracked for clients registering interests on PR.
geode-core/src/main/java/org/apache/geode/internal/cache/TombstoneService.java