/**
  * Creates a notification configuration with the given set of events.
  *
  * @param events the list of events for the notification configuration.
  */
 protected NotificationConfiguration(EnumSet<S3Event> events) {
   if (events != null) {
     for (S3Event s3Event : events) {
       this.events.add(s3Event.toString());
     }
   }
 }
 /**
  * Adds the given event to the set of events for this {@link NotificationConfiguration} object.
  *
  * @param event the event to add to this notification configuration
  */
 public void addEvent(S3Event event) {
   this.events.add(event.toString());
 }