private long maybeSendRequests(
        long currentTimeMs,
        Set<Node> destinations,
        Supplier<ApiMessage> requestSupplier
    ) {
        long minBackoffMs = Long.MAX_VALUE;
        for (Node destination : destinations) {
            long backoffMs = maybeSendRequest(currentTimeMs, destination, requestSupplier);
            if (backoffMs < minBackoffMs) {
                minBackoffMs = backoffMs;
            }
        }
        return minBackoffMs;
    }
Attempt to send a request. Return the time to wait before the request can be retried.
raft/src/main/java/org/apache/kafka/raft/KafkaRaftClient.java