@Override
    public List<String> listFunctions(String dbName) throws CatalogException {
        return Collections.emptyList();
    }
Append a new level to the base namespace
inlong-sort/sort-flink/sort-flink-v1.15/sort-connectors/iceberg/src/main/java/org/apache/inlong/sort/iceberg/FlinkCatalog.java