/// <summary>
        /// Activates the loading screen.
        /// </summary>
        public static void Load( ScreenManager screenManager, bool loadingIsSlow,
                                params GameScreen[] screensToLoad )
        {
            // Tell all the current screens to transition off.
            foreach( GameScreen screen in screenManager.GetScreens() )
                screen.ExitScreen();

            // Create and activate the loading screen.
            LoadingScreen loadingScreen = new LoadingScreen( screenManager,
                                                            loadingIsSlow,
                                                            screensToLoad );

            screenManager.AddScreen( loadingScreen );
        }