Dot.Net Core3.1API中GetCookies方法的扩展类是什么？

using Microsoft.AspNetCore.Http;
using System.Linq;

public static class CookieExtensions
{
    /// <summary>
    /// 获取指定名称的Cookie值，如果不存在则返回默认值。
    /// </summary>
    /// <param name="request">HttpRequest对象。</param>
    /// <param name="name">Cookie的名称。</param>
    /// <param name="defaultValue">如果Cookie不存在，则返回此默认值。</param>
    /// <returns>Cookie的值或默认值。</returns>
    public static string GetCookieOrDefault(this HttpRequest request, string name, string defaultValue = null)
    {
        if (request == null)
        {
            throw new ArgumentNullException(nameof(request));
        }

        var cookie = request.Cookies[name];
        return cookie ?? defaultValue;
    }

    /// <summary>
    /// 获取所有Cookie，并以键值对的形式返回。
    /// </summary>
    /// <param name="request">HttpRequest对象。</param>
    /// <returns>所有Cookie的键值对集合。</returns>
    public static IReadOnlyDictionary<string, string> GetAllCookies(this HttpRequest request)
    {
        if (request == null)
        {
            throw new ArgumentNullException(nameof(request));
        }

        return request.Cookies.ToDictionary(c => c.Key, c => c.Value);
    }
}

[HttpGet]
public IActionResult Get()
{
    var userId = Request.GetCookieOrDefault("UserId", "guest");
    var allCookies = Request.GetAllCookies();

    // 进一步处理逻辑...

    return Ok(new { UserId = userId, AllCookies = allCookies });
}