@Override
        public void onPartitionsRevoked(final Collection<TopicPartition> partitions) {
            for (final TopicPartition partition : partitions) {
                assignedTopics.remove(partition.topic());
            }
            listener.onPartitionsRevoked(partitions);
        }
End-to-end integration test based on using regex and named topics for creating sources, using
an embedded Kafka cluster.
streams/src/test/java/org/apache/kafka/streams/integration/RegexSourceIntegrationTest.java