public void setAsPossibleDuplicate(Object key) {
    Object object = optimalGet(key);
    if (object != null) {
      ((GatewaySenderEventImpl) object).setPossibleDuplicate(true);
    }
  }
Overriding this method from AbstractBucketRegionQueue in order to remove the event from
eventSeqNumQueue if EntryNotFoundException is encountered during basicDestroy. This change is
done during selective merge from r41425 from gemfire701X_maint.
geode-core/src/main/java/org/apache/geode/internal/cache/BucketRegionQueue.java