Symfony 4: Overriding Twig's routing functions

I've tried to override path and url functions with the answer there : https://stackoverflow.com/a/72365709/2356946But it's not overriding functions. I mean, even with forcing getPath to do crazy thing (adding &testing=testing to every generated path for example), it seems that my code is not executed...

Any idea why my functions are not overriding the original ones?