@Nullable
    @Override
    public SourceRecords nextRecordFromSplit() {
        final Iterator<SourceRecords> 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.
Copy from com.ververica:flink-cdc-base:2.3.0.
inlong-sort/sort-flink/cdc-base/src/main/java/org/apache/inlong/sort/cdc/base/source/meta/split/ChangeEventRecords.java