**CLASS** # `GTUIApp` The GTUI application. ## Properties ### `updateHandlers` The handlers which are called when a state changes. ### `body` The app's content. ### `sceneStorage` The scenes that are displayed. ## Methods ### `init(_:body:)` Initialize the GTUI application. - Parameters: - id: The application id. - body: The application's content. ### `onActivate()` The entry point of the application.