private void unscheduleTombstone(RegionEntry entry, boolean validate) {
    incTombstoneCount(-1);
    if (logger.isTraceEnabled(LogMarker.TOMBSTONE_VERBOSE)) {
      logger.trace(LogMarker.TOMBSTONE_VERBOSE,
          "unscheduling tombstone for {} count is {} entryMap size is {}", entry.getKey(),
          tombstoneCount.get(), entries.size()/* , new Exception("stack trace") */);
    }
    if (logger.isTraceEnabled(LogMarker.TOMBSTONE_COUNT_VERBOSE) && validate) {
      if (entries instanceof AbstractRegionMap) {
        ((AbstractRegionMap) entries).verifyTombstoneCount(tombstoneCount);
      }
    }
    // we don't have to remove the entry from the sweeper since the version has
    // changed. It would be costly to iterate over the tombstone list for
    // every tombstone exhumed while holding the entry's lock
    // this.cache.getTombstoneService().unscheduleTombstone(entry);
  }
regions track the number of tombstones their map holds for size calculations
geode-core/src/main/java/org/apache/geode/internal/cache/LocalRegion.java