private static ITheme GetThemeByIndex(int i) { switch (i) { case 0: return(PlatformTheme ?? throw new InvalidOperationException()); case 1: return(DefaultTheme.Create()); case 2: return(AlternateBordersTheme.Create()); case 3: return(SimpleTheme.CreateBlack()); case 4: return(SimpleTheme.CreateWhite()); case 5: return(SimpleTheme.CreateBlue()); case 6: return(StylishTheme.CreateRed()); case 7: return(StylishTheme.CreateBlue()); default: throw new IndexOutOfRangeException(); } }