protected override void OnInitialize()
{
base.OnInitialize();
Begin.Merge(End).Skip(2).CatchSubscribe(_ => Update(), CloseCancellation);
IsSentSelected.Merge(IsDeletedSelected).Merge(IsCurrentSelected)
.Where(_ => IsCurrentSelected ^ IsSentSelected.Value ^ IsDeletedSelected.Value)
.CatchSubscribe(_ => Update(), CloseCancellation);
}