Testnative application

Whoever can answer this:

I have a question regarding the testnative application in the test suite. I
noticed that it’s setup to open native windows from X11, Windows, and
Cocoa. The issue is, there is no implementation C file for Cocoa, so I’m
unable to build and run this test application on Mac OS X. It’s setup fine
in the testnative.c and testnative.h files to work, there’s just no

Is this an error or has it simply not been written yet?