@Nullable
    public Offset getStartingOffset() {
        return startingOffset;
    }
The state of split to describe the change log of table(s).
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/StreamSplitState.java