public override void ViewWillTransitionToSize(CGSize size, IUIViewControllerTransitionCoordinator coordinator)
{
base.ViewWillTransitionToSize(size, coordinator);
coordinator.AnimateAlongsideTransitionInView(CollectionView, (context) =>
{
var isPortrait = size.Height > size.Width;
var space = this.PickerConfig.AlbumItemSpace(isPortrait: isPortrait);
var insets = this.CollectionView.ContentInset;
this.CollectionView.ContentInset = new UIEdgeInsets(top: insets.Top, left: space, bottom: insets.Bottom, right: space);
this.UpdateLayout(layout: this.CollectionView.CollectionViewLayout, isPortrait: isPortrait);
}, (_) => { });
}