Xbox controller extends generic Gamepad

I have a few input actions bound to the generic gamepad button north, south east and west. Using an xbox gamepad on a PC these actions are fired by the A,B,X,Y buttons. All good and as expected. The xbox controller shows up as a device which Extends: Gamepad. How do I define a custom device which extends Gamepad? I’ve created a custom device in c# but the documentation talks about Json templates and I can’t find any of those. Also the InputSystem.RegisterTemplate method doesn’t exist?

Could someone point me in the right direction please.

 

I'll answer my own post.

The docs don't seem to quite match the current API and as this is a work in progress that can be excused. I derived the custom device from the Gamepad class rather than the InputDevice class and added my own state class. The custom device then shows up as "Extends: Gamepad". Now any actions bound to the generic gamepad device are fired when I update the state of the custom device.