Widget closed customization

In my project, I want to a couple widgets are being minimized always on the UI. It means the closed function should be changed to minimized. I tried the piece of code from Robert below:
for each (var widgetId:Number in ViewerContainer.getInstance().widgetManager.getAllLoadedWidgetIds()) {
if(widgetId != 2) {
var data:Object = {
id: widgetId,
state: WidgetStates.WIDGET_MINIMIZED
};
AppEvent.dispatch(AppEvent.WIDGET_CHANGE_STATE, data);
}
}
But it does not work. Please kindly provide your help if you can. Thanks.