lazy var photos: [INSPhotoViewable] = {

    return [

        INSPhoto(imageURL: URL(string: "http://1.jpg"), thumbnailImage: UIImage(named: "thumbnailImage")!),

        INSPhoto(imageURL: URL(string: "http://2.jpg"), thumbnailImage: UIImage(named: "thumbnailImage")!),

        INSPhoto(imageURL: URL(string: "http://3.jpg"), thumbnailImageURL: URL(string: "thumbnailImage")),

        INSPhoto(imageURL: URL(string: "http://4.jpg"), thumbnailImageURL: URL(string: "thumbnailImage")),

        INSPhoto(imageURL: URL(string: "http://5.jpg"), thumbnailImageURL: URL(string: "thumbnailImage"))

    ]
}()

let imgUrlArr = ["http://1.jpg", "http://2.jpg", "http://3.jpg", "http://4.jpg"]
var photos: [INSPhotoViewable] = imgUrlArr.map { INSPhoto(imageURL: URL(string: $0), thumbnailImage: UIImage(named: "thumbnailImage")!) }