Android what means "refactoring across test artifacts"

I am currently looking the video Android Testing (Android Dev Summit 2015) . It is mentionned the possibility to refactor across test artifact. At 16:20 in the video, Jorge Alcérreca says "...you will be able to refactor across Test Artifacts, if you know what I am talking about, you know this is huge"...

Well, I don't know what he is talking about, can someone give me some clue?