How to write MassTransitStateMachine unit tests?

I'm finally starting to leverage the excellent Automatonymous components within MassTransit, and I'd like to TDD my way through my new state machines.

After reading over the MT docs here (http://masstransit-project.com/MassTransit/advanced/sagas/automatonymous.html) and spending some time Googling, I found unit tests right in the MT/Automatonymous Git repo that looked like the way to go:

https://github.com/MassTransit/Automatonymous/blob/master/src/Automatonymous.Tests/Condition_Specs.cs#L21

In particular, the _machine.RaiseEvent(....) method seemed to be exactly what I needed to be able to drive the state machine with test-provided stimuli.

Next, I went hunting for that overload... Turns out it's an extension method that appears to live here:

https://github.com/MassTransit/Automatonymous/blob/15e9181ed05e37ff71e85b514aafc351b1edf27f/src/Automatonymous/RaiseEventExtensions.tt

That's where I've gotten stuck. I'm not sure what the right way is to make use of these extension methods for testing? *.tt is a text generation template format... Are these installed as part of the nuget package? How do I gain access to the extensions? and/or more broadly, what is the recommended way to write unit tests for state machines inheriting from MassTransitStateMachine<T>?

Follow-up question here: How to successfully drive a MassTransitStateMachine via the InMemoryTestHarness?

The test you reference are not from MassTransit but from the Automatonymous library, which is not part of MassTransit.

What you are looking for can be probably found here:

State machine saga tests using the test framework. The issue is that the test framework is coupled to NUnit
"Classic" saga tests using the test harness. The test harness is framework-agnostic but there are no tests that combine state machines and test harness, at least in the main repo.
State machine saga tests using the test hardness, outside of the main repo. This is my project and I use xUnit, since I am using the test harness, it is fine. However, you can see that one test is skipped and I don't remember exactly what was the issue but there was something there I couldn't resolve. This might be related to the persistence that I test though.