@AfterAll
    public static void close() {
        CONNECT_CLUSTERS.values().forEach(EmbeddedConnectCluster::stop);
        // wait for all blocked threads created while testing zombie task scenarios to finish
        BlockingConnectorTest.Block.join();
    }
Integration tests for Kafka Connect's connector offset management REST APIs
connect/runtime/src/test/java/org/apache/kafka/connect/integration/OffsetsApiIntegrationTest.java