public NotFoundPageMiddleware(RequestDelegate next,
                               ILoggerFactory loggerFactory,
                               RequestTracker requestTracker,
                               IOptions <NotFoundMiddlewareOptions> options)
 {
     _next           = next;
     _requestTracker = requestTracker;
     _logger         = loggerFactory.CreateLogger <NotFoundPageMiddleware>();
     _options        = options.Value;
 }