private List<CompletableFuture<Map<TopicPartition, OffsetAndMetadata>>> sendAndVerifyDuplicatedOffsetFetchRequests(
            final CommitRequestManager commitRequestManager,
            final Set<TopicPartition> partitions,
            int numRequest,
            final Errors error) {
        List<CompletableFuture<Map<TopicPartition, OffsetAndMetadata>>> futures = new ArrayList<>();
        long deadlineMs = time.milliseconds() + defaultApiTimeoutMs;
        for (int i = 0; i < numRequest; i++) {
            futures.add(commitRequestManager.fetchOffsets(partitions, deadlineMs));
        }

        NetworkClientDelegate.PollResult res = commitRequestManager.poll(time.milliseconds());
        assertEquals(1, res.unsentRequests.size());
        res.unsentRequests.get(0).handler().onComplete(buildOffsetFetchClientResponse(res.unsentRequests.get(0),
            partitions, error));
        res = commitRequestManager.poll(time.milliseconds());
        assertEquals(0, res.unsentRequests.size());
        return futures;
    }
@return Retriable coordinator errors and a boolean indicating if it is expected to mark
the coordinator unknown when the error occurs.
clients/src/test/java/org/apache/kafka/clients/consumer/internals/CommitRequestManagerTest.java