So, in the
body contains a reference to the specific body instance that was contacted. So, in that method, you want to use
body to reference that instance.
Without seeing some code, I'm just guessing, but I assume the the greenslime instance you created "manually" via
.instance() (in your above example) is a different, separate instance of the same scene. So, calling
dead() on that instance should work (for that instance), it will not impact any other instance.
So, bottom line, I assume you have (at least) 2 independent greenslime instances in the scene in your test. Interacting with one will not impact the other.