afterModel argument transition

What is exactly transition in Ember route afterModel method? The first argument is well explained but not the second. Checking Ember API classes I cannot find any clue of Transition class.

So what exactly is transition?

Isn’t it the same transition as was passed to the model. The one that brought the thread of execution to that route.

What is transition to be exact? Is it class with properties? Or asking it another way, transition is an instance of which class?

http://emberjs.joefiorini.com/api/classes/Transition.html Found this on web

Did you check the version? It seems v.1.0.x In Ember API that class does not exist. I guess I will have to use Console.Log

Transition is from router.js library. Detail is here