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

	@Override
	public TypeInformation<OUT> getProducedType() {
		return deserializationSchema.getProducedType();
	}

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

}