/// <summary>
    /// Adds MVC data annotations localization to the application.
    /// </summary>
    /// <param name="builder">The <see cref="IMvcBuilder"/>.</param>
    /// <param name="setupAction">The action to configure <see cref="MvcDataAnnotationsLocalizationOptions"/>.
    /// </param>
    /// <returns>The <see cref="IMvcBuilder"/>.</returns>
    public static IMvcBuilder AddDataAnnotationsLocalization(
        this IMvcBuilder builder,
        Action <MvcDataAnnotationsLocalizationOptions>?setupAction)
    {
        if (builder == null)
        {
            throw new ArgumentNullException(nameof(builder));
        }

        DataAnnotationsLocalizationServices.AddDataAnnotationsLocalizationServices(
            builder.Services,
            setupAction);

        return(builder);
    }
 // Internal for testing.
 internal static void AddDataAnnotationsLocalizationServices(
     IServiceCollection services,
     Action <MvcDataAnnotationsLocalizationOptions> setupAction)
 {
     DataAnnotationsLocalizationServices.AddDataAnnotationsLocalizationServices(services, setupAction);
 }