vertical(layoutSize:subitem:count:)
Creates a group of the specified size, containing an array of equally sized items arranged in a vertical line up to the number specified by count.
Declaration
class func vertical(layoutSize: NSCollectionLayoutSize, subitem: NSCollectionLayoutItem, count: Int) -> SelfDiscussion
When you set a value for the interItemSpacing property after using this initializer, the group keeps the same number of items and automatically resizes them to add the extra specified spacing between them.