How to use the scratch-gui.initLocale function in scratch-gui

}
    if (parts.indexOf('fullscreen') !== -1) {
        guiInitialState = GUI.initFullScreen(guiInitialState);
    }
    return guiInitialState;
};

render(
    ,
    document.getElementById('app'),
    {
        preview: previewActions.previewReducer,
        ...GUI.guiReducers
    },
    {
        locales: GUI.initLocale(GUI.localesInitialState, window._locale),
        scratchGui: initGuiState(GUI.guiInitialState)
    },
    GUI.guiMiddleware
);