@Override
    public void connectorConfig(String connName, final Callback<Map<String, String>> callback) {
        log.trace("Submitting connector config read request {}", connName);
        super.connectorConfig(connName, 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