public NancyMiddleware(RequestDelegate next, NancyOptions options)
        {
            _next = next;

            _options = options;
            _options.Bootstrapper.Initialise();
            _engine = _options.Bootstrapper.GetEngine();
        }
 /// <summary>
 /// Tells the NancyMiddleware to pass through when
 /// response has one of the given status codes.
 /// </summary>
 /// <param name="nancyOptions">The Nancy options.</param>
 /// <param name="httpStatusCode">The HTTP status code.</param>
 public static void PassThroughWhenStatusCodesAre(this NancyOptions nancyOptions, params HttpStatusCode[] httpStatusCode)
 {
     nancyOptions.PerformPassThrough = context => httpStatusCode.Any(code => context.Response.StatusCode == code);
 }