Stops all running animations for region_id and all animatable
regions underneath.
A NULLregion_id will stop all ongoing animations in context,
when dealing with a gtk.StyleContext obtained through
Widget.getStyleContext, this is normally done for you
in all circumstances you would expect all widget to be stopped,
so this should be only used in complex widgets with different
animatable regions.
Stops all running animations for region_id and all animatable regions underneath.
A NULL region_id will stop all ongoing animations in context, when dealing with a gtk.StyleContext obtained through Widget.getStyleContext, this is normally done for you in all circumstances you would expect all widget to be stopped, so this should be only used in complex widgets with different animatable regions.