code: public void sendNotification(Object message, String subject) {
  		this.convertAndSend(getRequiredDefaultDestination(), message, Collections
  				.singletonMap(TopicMessageChannel.NOTIFICATION_SUBJECT_HEADER, subject));
  	}
docs: Convenience method that sends a notification with the given {@literal message} and
  {@literal subject} to the {@literal destination}. The {@literal subject} is sent as
  header as defined in the
  <a href="https://docs.aws.amazon.com/sns/latest/dg/json-formats.html">SNS message
  JSON formats</a>. The configured default destination will be used.
  @param message The message to send
  @param subject The subject to send