final class UserManager {

    var service: UserPhotoService

    init(service: UserPhotoService) {
        self.service = service
    }

    func fetchUserPhoto(by userId: String) {
        service.fetchUserPhoto(by: userId) { (userPhoto, error) in
            guard error == nil else {
                //SHOW ERROR ON VIEW
                return
            }
            //SHOW FETCH SUCCESS AND DISPLAY FETCHED PHOTO

        }
    }
}