如何在Kestrel中获取HTTP请求头的Span<Byte>

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using System;

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        // 添加ASP.NET Core的服务
        services.AddMvc();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseRouting();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapGet("/", async context =>
            {
                // 获取HTTP请求头
                var request = context.Request;
                var headers = request.Headers;
                var headerName = "HeaderName"; // 替换成你要获取的请求头的名称

                if (headers.ContainsKey(headerName))
                {
                    // 获取请求头的值，并将其转换为Span<Byte>
                    var headerValue = headers[headerName];
                    var headerBytes = new Span<byte>(new byte[headerValue.Count]);
                    headerValue.CopyTo(headerBytes);

                    // 在控制台打印请求头的Span<Byte>
                    Console.WriteLine(headerBytes.ToString());
                }

                await context.Response.WriteAsync("Hello World!");
            });
        });
    }
}