@Nullable
    @Override
    public SourceRecord nextRecordFromSplit() {
        final Iterator<SourceRecord> recordsForSplit = this.recordsForCurrentSplit;
        if (recordsForSplit != null) {
            if (recordsForSplit.hasNext()) {
                return recordsForSplit.next();
            } else {
                return null;
            }
        } else {
            throw new IllegalStateException();
        }
    }
An implementation of {@link RecordsWithSplitIds} which contains the records of one table split.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/mysql-cdc/src/main/java/org/apache/inlong/sort/cdc/mysql/source/split/MySqlRecords.java