"RosterGroup" filtering not allowed, this is funny

public override function set filterFunction(f:Function):void
throw new Error(“Setting the filterFunction on RosterGroup is not allowed; Wrap it in a ListCollectionView and filter that.”);

this is radicoulas, can this be fixed? RosterGroup is ArrayCollection which is ListCollectionView I dond understand why it is neccessary to wrap RosterGroup inside another ListCollectionView that sounds extremly inefficient.

RosterGroups are model objects, filtering is typically a view concept. If you filter a RosterGroup then every other part of the program that uses it will get the filtered version as well. Have you tested to see if this is actually causing performance issues? In my testing almost all perf issues in SparkWeb were caused by mx:List, not by ListCollectionView.