@Override
    public DescribeDelegationTokenResult describeDelegationToken(final DescribeDelegationTokenOptions options) {
        final KafkaFutureImpl<List<DelegationToken>>  tokensFuture = new KafkaFutureImpl<>();
        final long now = time.milliseconds();
        runnable.call(new Call("describeDelegationToken", calcDeadlineMs(now, options.timeoutMs()),
            new LeastLoadedNodeProvider()) {

            @Override
            DescribeDelegationTokenRequest.Builder createRequest(int timeoutMs) {
                return new DescribeDelegationTokenRequest.Builder(options.owners());
            }

            @Override
            void handleResponse(AbstractResponse abstractResponse) {
                DescribeDelegationTokenResponse response = (DescribeDelegationTokenResponse) abstractResponse;
                if (response.hasError()) {
                    tokensFuture.completeExceptionally(response.error().exception());
                } else {
                    tokensFuture.complete(response.tokens());
                }
            }

            @Override
            void handleFailure(Throwable throwable) {
                tokensFuture.completeExceptionally(throwable);
            }
        }, now);

        return new DescribeDelegationTokenResult(tokensFuture);
    }
Fail futures in the given Map which were retried due to exceeding quota. We propagate
the initial error back to the caller if the request timed out.
clients/src/main/java/org/apache/kafka/clients/admin/KafkaAdminClient.java