@Override
  protected boolean supportsConcurrencyChecks() {
    return false;
  }
Holds keys for those events that were not found in BucketRegionQueue during processing of
ParallelQueueRemovalMessage. This can occur due to the scenario mentioned in #49196.
geode-core/src/main/java/org/apache/geode/internal/cache/AbstractBucketRegionQueue.java