@Override
    public String toString() {
        return "LastRecord(" +
                "lastDataOffset=" + lastDataOffset +
                ", producerEpoch=" + producerEpoch +
                ')';
    }
The last written record for a given producer. The last data offset may be undefined
if the only log entry for a producer is a transaction marker.
storage/src/main/java/org/apache/kafka/storage/internals/log/LastRecord.java