private static void assertInitialLoadFuturesNotComplete(List<StandardAuthorizer> authorizers) {
        for (int i = 0; i < authorizers.size(); i++) {
            assertFalse(authorizers.get(i).initialLoadFuture().isDone(),
                "authorizer " + i + " should not have completed loading.");
        }
    }
Test that certain controller operations finish immediately without putting an event
on the controller queue, if there is nothing to do.
metadata/src/test/java/org/apache/kafka/controller/QuorumControllerTest.java