code: public BucketNotificationConfiguration addConfiguration(String name,
              NotificationConfiguration notificationConfiguration) {
          configurations.put(name, notificationConfiguration);
          return this;
      }
docs: Adds the given notification configuration to the
  {@link BucketNotificationConfiguration} object
  
  @param name
  the name of the configuration
  @param notificationConfiguration
  the notification configuration for the Amazon S3 bucket.
  @return The updated {@link BucketNotificationConfiguration} object.