@Override
    public void healthCheck(Callback<Void> callback) {
        addRequest(
                () -> {
                    callback.onCompletion(null, null);
                    return null;
                },
                forwardErrorAndTickThreadStages(callback)
        );
    }
Close resources managed by this herder but which are not explicitly started.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/DistributedHerder.java