static let tweakManager: TweakManager = { // mutable configuration (to override tweaks from other configurations) let userDefaultsConfiguration = UserDefaultsConfiguration(userDefaults: .standard) // remote configurations (optional) let optimizelyConfiguration = OptimizelyConfiguration() let firebaseConfiguration = FirebaseConfiguration() // local JSON configuration (default tweaks) let jsonFileURL = Bundle.main.url(forResource: "Tweaks", withExtension: "json")!