        let profileBackgroundUrlString = dictionary["profile_background_image_url_https"] as? String
        
        if let profileBackgroundUrlString = profileBackgroundUrlString {
            profileBackgroundUrl = NSURL(string: profileBackgroundUrlString)
        }

        
        tagline = dictionary["description"] as? String
    }
    
    // 'computed properties' - not a piece of storage associated with var
    static var _currentUser: User?
    
    static let userDidLogoutNotification = "UserDidLogout"
    