Gtk.ThemingEngine.prototype.get_style_property
function get_style_property(property_name:String, value:GObject.Value):void {
    // Gjs wrapper for gtk_theming_engine_get_style_property()
}Gets the value for a widget style property.
Since 3.0
- property_name
- the name of the widget style property 
- value
- Return location for the property value, free with GObject.unset after use.