code: public List<TopicConfiguration> getTopicConfigurations() {
          List<TopicConfiguration> topicConfigs = new ArrayList<BucketNotificationConfiguration.TopicConfiguration>();
          for (Map.Entry<String, NotificationConfiguration> entry : configurations
                  .entrySet()) {
              if (entry.getValue() instanceof TopicConfiguration) {
                  topicConfigs.add((TopicConfiguration) entry.getValue());
              }
          }
          return topicConfigs;
      }
docs: <p>
  Gets the list of
  {@link BucketNotificationConfiguration.TopicConfiguration} objects
  contained in this object. This method may return an empty list if no
  <code>TopicConfiguration</code> objects are present.
  </p>
  <p>
  This method is deprecated and will not return all the notification
  configuration associated with the Amazon S3 bucket. To retrieve all the
  configuration use @see
  BucketNotificationConfiguration#getConfigurations()
  </p>
  
  @deprecated
  @see BucketNotificationConfiguration#getConfigurations()
  @return The list of <code>TopicConfiguration</code> objects contained in
  this object. May return an empty list.