Is there any way to add Layer groups in ArcGIS Flex Viewer layer widget? For example I have about 30 layers that are all other companies fiber networks. I would love for the user to be able to turn those all on or off at once. It is a burden for the end user to have to turn them all on and off one by one. The image below shows only some of the layers that need to be turned on individually, as you can see it would be cumbersome.