@Test
    public void testAlterSourceConnectorOffsetsCustomOffsetsTopic() throws Exception {
        Map<String, String> connectorConfigs = baseSourceConnectorConfigs();
        connectorConfigs.put(SourceConnectorConfig.OFFSETS_TOPIC_CONFIG, "custom-offsets-topic");
        alterAndVerifySourceConnectorOffsets(connectorConfigs);
    }
Integration tests for Kafka Connect's connector offset management REST APIs
connect/runtime/src/test/java/org/apache/kafka/connect/integration/OffsetsApiIntegrationTest.java