How can I get a list of all addon shortcuts as displayed in Manage Extension Shortcuts?

I need a listing of the shortcuts displayed in under in Manage Extension Shortcuts in about:addons.

Is there an API for that, or some pointer to the code in Firefox which creates that list?

I have lots of addons and it is frustrating to try to set a shortcut for your commonly used addons only to find out that some little used addon has taken it over.