Set a default content-type with an OWIN middleware

DefaultContentType.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Gate;
using Gate.Kayak;
using Nancy.Hosting.Owin;
using Gate.Helpers;

namespace KayakNancyTest01
{
    public class Startup
    {
        public static void Configuration(IAppBuilder builder)
        {
            builder
                .RescheduleCallbacks()
                .Use(del => (env, result, fault) => {
                    del(env, (status, headers, body) => {
                        if (!headers.ContainsKey("Content-Type") || string.IsNullOrEmpty(headers["Content-Type"]))
                            headers["Content-Type"] = "text/html";
                        result(status, headers, body);
                    }, fault);
                })
                .RunNancy();
        }
    }
}