Mystified by upgrade from v2 to v4

I apologise if this is a dumb or repetitive question, but I’m completely mystified by the upgrade to v4, it doesn’t appear to have a media object, not that I can figure out.

I used the standalone library to build a video player with my own interface and controls, and v2 passed a media object back through the success callback, and that had methods like play() and so on that I could call from my UI.

But v4 doesn’t have that. So where is the media object that the library creates?