[TYPO3] Restricting user access to contextual menu items

[Mike]

I wrote a module that adds a contextual menuitem to the Page tree in the 
admin.  I only want one user, the superadmin, to be able to see it when 
he right-clicks.  How do I do that?

When I edit a (non-superadmin) user/group, my module is *not* turned on 
in the list of modules available to them (in "Select available backend 
modules for the user."), but my menuitem still shows up in their 
right-click menu of a page in the Page tree.

v 4.1.2

thanks