private void maybeOverrideRetryBackoffMs() {
            // We only want to reduce the backoff when retrying the first AddPartition which errored out due to a
            // CONCURRENT_TRANSACTIONS error since this means that the previous transaction is still completing and
            // we don't want to wait too long before trying to start the new one.
            //
            // This is only a temporary fix, the long term solution is being tracked in
            // https://issues.apache.org/jira/browse/KAFKA-5482
            if (partitionsInTransaction.isEmpty())
                this.retryBackoffMs = ADD_PARTITIONS_RETRY_BACKOFF_MS;
        }
Returns the first inflight sequence for a given partition. This is the base sequence of an inflight batch with
the lowest sequence number.
@return the lowest inflight sequence if the transaction manager is tracking inflight requests for this partition.
        If there are no inflight requests being tracked for this partition, this method will return
        RecordBatch.NO_SEQUENCE.
clients/src/main/java/org/apache/kafka/clients/producer/internals/TransactionManager.java