@Test
    public void testCloseCoordinatorNotKnownNoCommits() throws Exception {
        try (ConsumerCoordinator coordinator = prepareCoordinatorForCloseTest(true, false, Optional.empty(), true)) {
            makeCoordinatorUnknown(coordinator, Errors.NOT_COORDINATOR);
            closeVerifyTimeout(coordinator, 1000, 0, 0);
        }
    }
Verifies that subscription change updates SubscriptionState correctly even after JoinGroup failures
that don't re-invoke onJoinPrepare.
clients/src/test/java/org/apache/kafka/clients/consumer/internals/ConsumerCoordinatorTest.java