Carrier-sense multiple access with collision avoidance in DW1000

I’m having trouble locating the pseudo-CCA code within the sample code.
I have download the latest example code from https://github.com/Decawave/dwm1001-examples
Can you tell me the name of the C module that it is in?

A similar question was also asked at C Code user app for DWM1001 but I couldn’t find any mention of LBT or “Listen before talk” in the example code.

Any other pointers to carrier sensing and/or collision detection avoidance would also be useful.
My application has many radios that cannot be sync’d, so time/slotted solutions will not work for me.
I only need the ranges between devices, there is little other data being transmitted - ie lots of burst traffic.

Thanks.