Is there any client program which can test what extension the server support?

[Adam Q]

Sorry for disturbing everyone.

May someone tell me is there any client program that can test what
extension the X server supports?

I try "X -extension XX" command,it just shows the extensions that can
be run-time disabled.
However I am going to test another X server which runs in windows and
seems have no support for CLI parameters.
So is there some CLIENT program that can test what extension the X
server supports?

As far as I know,there is a request format in X protocol that can
query what extension the X server supports("Request: QueryExtenion" in
wireshark).
So if there is no compiled client program/package, is it hard to
archieve the goal by coding ?