code: public PubsubFuture<Void> deleteTopic(final String project,
                                          final String topic) {
      return deleteTopic(canonicalTopic(project, topic));
    }
docs: Delete a Pub/Sub topic.
  
  @param project The Google Cloud project.
  @param topic   The name of the topic to delete.
  @return A future that is completed when this request is completed. The future will be completed with {@code null}
  if the response is 404.