presto-main/src/main/java/io/prestosql/sql/planner/SystemPartitioningHandle.java/SystemPartitioningHandle/createSystemPartitioning
class SystemPartitioningHandle:    private static PartitioningHandle createSystemPartitioning(SystemPartitioning partitioning, SystemPartitionFunction function)
    {
        return new PartitioningHandle(Optional.empty(), Optional.empty(), new SystemPartitioningHandle(partitioning, function));
    }