code: protected static void preloadAndLaunch(final Class<? extends Application> appClass, final Class<? extends Preloader> preloaderClass, final String... args) {
          LauncherImpl.launchApplication(appClass, preloaderClass, args);
      }
docs: Launch the given JavaFX Application with given preloader.
  
  @param appClass the JavaFX application class to launch
  @param preloaderClass the preloader class used as splash screen with progress
  @param args arguments passed to java command line