asp.net 3.5 checkboxlist AddAttributesToRender Not called in Override

I recently came across this issue where in if we override the AddAttributesToRender method in our custom CheckBoxlist.

It never gets called at all.

Instead we had to use PreRender or RenderItem refer

https://www.dotnetmonster.com/Uwe/Forum.aspx/asp-net-controls-building/3261/checkboxlist-AddAttributesToRender

Is any one aware of a Msdn link confirming the same.