static List<KafkaMetric> cipherMetrics(Metrics metrics) {
        return metrics.metrics().entrySet().stream().
            filter(e -> e.getKey().description().
                contains("The number of connections with this SSL cipher and protocol.")).
            map(Map.Entry::getValue).
            collect(Collectors.toList());
    }
Send multiple requests to several connections in parallel. Validate that responses are received in the order that
requests were sent.
clients/src/test/java/org/apache/kafka/common/network/SelectorTest.java