private Deque<NetworkClient.InFlightRequest> requestQueue(String node) {
        Deque<NetworkClient.InFlightRequest> reqs = requests.get(node);
        if (reqs == null || reqs.isEmpty())
            throw new IllegalStateException("There are no in-flight requests for node " + node);
        return reqs;
    }
Get the request queue for the given node
clients/src/main/java/org/apache/kafka/clients/InFlightRequests.java