public boolean isUnavailable(Node node) {
        lock.lock();
        try {
            return NetworkClientUtils.isUnavailable(client, node, time);
        } finally {
            lock.unlock();
        }
    }
Check if the code is disconnected and unavailable for immediate reconnection (i.e. if it is in
reconnect backoff window following the disconnect).
clients/src/main/java/org/apache/kafka/clients/consumer/internals/ConsumerNetworkClient.java