1. visit the useradmin portal, http://localhost:4502/useradmin
2. Create new user group, "cannot_delete_pages".
3. add the group "authors" into this group.
4. edit the user group, cannot_delete_pages, to "disallow page deletion on /content
5. press save.
6. find the user group, and validate changes
7. assign the group to a user, and test!