NumerableIcon.setBackgroundIconName

Updates the icon to use the icon named icon_name from the current icon theme as the base background image. If icon_name is null, self will go back using style information or default theming for its background image.

If this method is called and a #GIcon was already set as background for the icon, icon_name will be used, i.e. the last method called between [gtk.numerable_icon.NumerableIcon.setBackgroundIconName] and [gtk.numerable_icon.NumerableIcon.setBackgroundGicon] has always priority.