assistance for "Use frameState.afterRender to fire QuadtreePrimitive.tileLoadProgressEvent #3450 "

Hello,

       I am willing to work on this issue and I need some assistance for it. What I understood from it is, Currently we are using Event.raiseEvent() to fire QuadtreePrimitive.tileLoadProgressEvent, but it should be now modified to fire using frameState.afterRender.push(function()).

      Please assist me wheter I am going on the right path or not.

Thanks.