public static void RemoveOnUI <T>(this ICollection <T> collection, T item)
{
Func <T, bool> removeMethod = collection.Remove;
DispatcherHelper.CheckBeginInvokeWithArgsOnUI(removeMethod, item);
}
public static void AddOnUI <T>(this ICollection <T> collection, T item)
{
Action <T> addMethod = collection.Add;
DispatcherHelper.CheckBeginInvokeWithArgsOnUI(addMethod, item);
}