public List<String> nodesWithTimedOutRequests(long now) {
        List<String> nodeIds = new ArrayList<>();
        for (Map.Entry<String, Deque<NetworkClient.InFlightRequest>> requestEntry : requests.entrySet()) {
            String nodeId = requestEntry.getKey();
            Deque<NetworkClient.InFlightRequest> deque = requestEntry.getValue();
            if (hasExpiredRequest(now, deque))
                nodeIds.add(nodeId);
        }
        return nodeIds;
    }
Returns a list of nodes with pending in-flight request, that need to be timed out

@param now current time in milliseconds
@return list of nodes
clients/src/main/java/org/apache/kafka/clients/InFlightRequests.java