in flink-connector-gcp-pubsub/src/main/java/org/apache/flink/streaming/connectors/gcp/pubsub/PubSubSink.java [340:344]
public void onFailure(Throwable t) {
ackAndMaybeNotifyNoPendingFutures();
exceptionAtomicReference.set(
new RuntimeException("Failed trying to publish message", t));
}