Array of panel objects.
Array, default = []
The code below shows the structure of the panel object: If you change this array during run-time you will need to call .refresh() method to update layout on the screen. It is not recommended to change this array after the object has been created. You should use .set() method to change panels dynamically, which will refresh the panel you changed. As of version 1.2+ you can add w2tabs or/and w2toolbar object at the top of the panel.