@Override
    public void notifyCheckpointComplete(long checkpointId) {
        // we have waited for at-least one complete checkpoint after all snapshot-splits are
        // finished, then we can mark snapshot assigner as finished.
        if (checkpointIdToFinish != null && !assignerFinished && allSplitsFinished()) {
            assignerFinished = checkpointId >= checkpointIdToFinish;
            LOG.info("Snapshot split assigner is turn into finished status.");
        }
    }
Assigner for snapshot 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/assigner/SnapshotSplitAssigner.java