@Override
        public Iterable<? extends RecordBatch> batches() {
            if (memoryRecords == null) {
                Iterator<RecordBatch> iterator = elasticLogFileRecords.batchIterator(startOffset, maxOffset, fetchSize);
                return (Iterable<RecordBatch>) () -> iterator;
            } else {
                return memoryRecords.batches();
            }
        }
Return the largest timestamp of the messages after a given offset

@param startOffset The starting offset.
@return The largest timestamp of the messages after the given position.
core/src/main/scala/kafka/log/streamaspect/ElasticLogFileRecords.java