@Override
    public void open() {
        snapshotSplitAssigner.open();
    }
Assigner for Hybrid split which contains snapshot splits and stream splits.
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/HybridSplitAssigner.java