NLA's properties file?

I was wondering where is the script for NLA’s properties. It is the one when you press N under NLA op.

I looked in the ui folder and can’t find anything about it.

Thanks,
Joyce

This is hardcoded in C

Is it possible to hide some control in NLA’s property panel ?

I am creating a toolkit in Blender for animating a robot. I wanna customize my UI and combine/ hide some default UI. Is it possible?

Thanks!