Trackpad support with ActionMaps?

I feel slightly embarrassed for asking but I can't figure this out. I wanted to test one of the pull requests on Github but I can't find the secret word combination that let's me bind Mac trackpad events to an ActionMap. Mouse0, mouse1, Joystick0...heck, I even tried touchdevice even though that's only for touchscreens.

Did I overlook something in ActionMap.cc or is it unsupported?