@Override
    public synchronized void connectorOffsets(String connName, Callback<ConnectorOffsets> cb) {
        log.trace("Fetching offsets for connector: {}", connName);
        super.connectorOffsets(connName, cb);
    }
Single process, in-memory "herder". Useful for a standalone Kafka Connect process.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/standalone/StandaloneHerder.java