How to run a part test?

I've tried all kinds of stuff but it's getting a bit frustrating. I am trying to run the Rover wheel S2 test (which shows up in the right click menu) and tagged it as testtag.

I've tried:

set tester to ship:partstagged("testtag"):GETMODULE.
print tester.

Neither does the following work:

set mod to ship:getmodule:("roverWheel2").
print mod:allevents.

How do I get to run the test event?