@Test
    public void testBlockInSourceTaskStart() throws Exception {
        log.info("Starting test testBlockInSourceTaskStart");
        createConnectorWithBlock(BlockingSourceConnector.class, TASK_START);
        Block.waitForBlock();

        createNormalConnector();
        verifyNormalConnector();
    }
Tests situations during which certain connector operations, such as start, validation,
configuration and others, take longer than expected.
connect/runtime/src/test/java/org/apache/kafka/connect/integration/BlockingConnectorTest.java