class PubSubSource extends RichSourceFunction<OUT> implements ResultTypeQueryable<OUT>, ParallelSourceFunction<OUT>, CheckpointListener, ListCheckpointed<AcknowledgeIdsForCheckpoint<String>> {

	@Override
	public void notifyCheckpointComplete(long checkpointId) throws Exception {
		acknowledgeOnCheckpoint.notifyCheckpointComplete(checkpointId);
	}

	  PubSubSource(PubSubDeserializationSchema<OUT> deserializationSchema,
				PubSubSubscriberFactory pubSubSubscriberFactory,
				Credentials credentials,
				int maxMessagesToAcknowledge,
				AcknowledgeOnCheckpointFactory acknowledgeOnCheckpointFactory);

}