We are facing the same problem in our current project. This is not an elegant solution using the API, but for now we will use a workaround to clear the HTML address of the groupβs landing page. The group identifier is displayed four times on this page in html by links. The most reliable way to search for an identifier is to search for "cid =", since it appears only once (now, anyway) on the page (what follows cid = is a numeric identifier). You will see what I mean when you look at the html pages of a group.
If you found a more effective solution, I would be grateful if you shared :)
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