public override int NumberOfViewsInCollectionView(CollectionViewBinding.PSCollectionView collectionView)
 {
     return _t.OnGetItemsInCollection();
 }
 public override CollectionViewBinding.PSCollectionViewCell ViewAtIndex(CollectionViewBinding.PSCollectionView collectionView, int viewAtIndex)
 {
     var v = collectionView.DequeueReusableView() as Cell ?? new Cell();
     _t.OnAssignObject(v, viewAtIndex);
     return v;
 }