Function getvid is not defined

Hi,
I created a brand new graph, and I copied your cycle_detection.gsql code from the Github page. I have a try on my platform and it says:

The tuple name or the function getvid is not defined.

Could anyone please kindly tell me what the problem is?Thanks a lot

The schema/data I used is really simple, which are below:

CREATE VERTEX Node (PRIMARY_ID id UINT, iid UINT)
CREATE UNDIRECTED EDGE Edge_ (FROM Node, TO Node)
CREATE GRAPH gsql_IEEE(*)

and the query is cycle_detection query I downloaded from your github page(the Rocha-Thatte algorithm).
Please contact me if you need more information.