default String splitId(TableId collectionId, int chunkId) {
        return collectionId.identifier() + ":" + chunkId;
    }
The {@link MongoDBChunkSplitter} used to split collection into a set of chunks for MongoDB data
source.
Copy from com.ververica:flink-connector-mongodb-cdc:2.3.0.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/mongodb-cdc/src/main/java/org/apache/inlong/sort/cdc/mongodb/source/assigners/splitters/SplitStrategy.java