public void stopWorker(long workerId, boolean mustDestroy) throws Throwable {
        try (ShutdownManager.Reference ref = shutdownManager.takeReference()) {
            stateChangeExecutor.submit(new StopWorker(workerId, mustDestroy)).get();
        } catch (ExecutionException e) {
            throw e.getCause();
        }
    }
Transitions a worker to WorkerDone.  Processed by the state change thread.
trogdor/src/main/java/org/apache/kafka/trogdor/agent/WorkerManager.java