ASP.NET Core Antiforgery with custom cache header value

AntiForgery.cs

using Microsoft.AspNetCore.Antiforgery.Internal;
using Microsoft.AspNetCore.Http;
using Microsoft.Net.Http.Headers;

public class Antiforgery : DefaultAntiforgery
{
	public Antiforgery(
		Microsoft.Extensions.Options.IOptions<Microsoft.AspNetCore.Antiforgery.AntiforgeryOptions> antiforgeryOptionsAccessor,
		IAntiforgeryTokenGenerator tokenGenerator,
		IAntiforgeryTokenSerializer tokenSerializer,
		IAntiforgeryTokenStore tokenStore,
		Microsoft.Extensions.Logging.ILoggerFactory loggerFactory)
		: base(antiforgeryOptionsAccessor, tokenGenerator, tokenSerializer, tokenStore, loggerFactory)
	{
	}

	protected override void SetDoNotCacheHeaders(HttpContext httpContext)
	{
		CacheControlHeaderValue.TryParse(httpContext.Response.Headers[HeaderNames.CacheControl][0], out CacheControlHeaderValue cacheControlHeader);
		if (cacheControlHeader == null)
		{
			cacheControlHeader = new CacheControlHeaderValue();
		}

		cacheControlHeader.NoCache = true;
		cacheControlHeader.NoStore = true;
		cacheControlHeader.MustRevalidate = true;
		httpContext.Response.Headers[HeaderNames.CacheControl] = cacheControlHeader.ToString();
		httpContext.Response.Headers[HeaderNames.Pragma] = "no-cache";
	}
}

Startup.cs

public class Startup
{
  public void ConfigureServices(IServiceCollection services)
  {
    services.AddSingleton<Microsoft.AspNetCore.Antiforgery.IAntiforgery, Antiforgery>();
  }
}