How come there's no way to close a media object when it's no longer in need.

I have a mediaview that constantly needs to be given a new Media object to play, but I don't see a method to close or dispose the previous media object before I make the switch.
The result of this is that, even though I no longer need a media file, I can't delete it or anything until I close the app because it is still being used somewhere in memory a la memory leak.