(solved) newMask does not work with captureBounds?

The Mask documentation says that it works with DisplayObjects. I am trying to apply a mask to a DisplayObject returned by captureBounds() but it is not working.

Is the documentation wrong or is it a bug?

Update: It is working. The mask that I was using (that I got from the Flashlight Sample) was simply to big, so all my content was fitting inside of the white part of the mask.