private void SetMenu(IAvnWindow avnWindow, ICollection <NativeMenuItemBase> menuItems) { if (menuItems is null) { menuItems = new List <NativeMenuItemBase>(); } var appMenu = avnWindow.ObtainMainMenu(); if (appMenu is null) { appMenu = _factory.CreateMenu(); } appMenu.Clear(); AddItemsToMenu(appMenu, menuItems); avnWindow.SetMainMenu(appMenu); }