Client-side equivalent of Entity:TestPVS( Vector )

Hello,

Im making an InfoHUD for my servers,

My issue is that I cannot seem to see a way of testing if something is in your PVS client-side;
As I want to hide the info about players not currently in your PVS as position/velocity etc will be incorrect.

Of course, I could send a netmsg to the server asking to test PVS then get the server to reply but that is a delay I do not really want if at all possible, and also always networking as a last resort.

If a client-side equivalent does not exist then how have you gotten round this sort of issue with your scripts?

Any and all help would be much appreciated,
Sam.