private void failAndRemoveExpiredFetchRequests() {
            Queue<OffsetFetchRequestState> requestsToPurge = new LinkedList<>(unsentOffsetFetches);
            requestsToPurge.forEach(RetriableRequestState::maybeExpire);
        }
Find the unsent fetch requests that have expired, remove them and complete their
futures with a TimeoutException.
clients/src/main/java/org/apache/kafka/clients/consumer/internals/CommitRequestManager.java