public Map<String, SchemalessSnapshotSplit> getAssignedSplits() {
        return assignedSplits;
    }
Returns whether the snapshot split assigner is finished, which indicates there is no more
splits and all records of splits have been completely processed in the pipeline.
inlong-sort/sort-flink/cdc-base/src/main/java/org/apache/inlong/sort/cdc/base/source/assigner/SnapshotSplitAssigner.java