@Override
            public void stop() {
                block.maybeBlockOn(TASK_STOP);
            }
{@link Thread#join(long millis) Await} the termination of all threads that have been
intentionally blocked either since the last invocation of this method or, if this method
has never been invoked, all threads that have ever been blocked.
connect/runtime/src/test/java/org/apache/kafka/connect/integration/BlockingConnectorTest.java