public boolean canSendMore(String node) {
        Deque<NetworkClient.InFlightRequest> queue = requests.get(node);
        return queue == null || queue.isEmpty() ||
               (queue.peekFirst().send.completed() && queue.size() < this.maxInFlightRequestsPerConnection);
    }
Can we send more requests to this node?

@param node Node in question
@return true iff we have no requests still being sent to the given node
clients/src/main/java/org/apache/kafka/clients/InFlightRequests.java