public static IAppBuilder UseClaimsTransformation(this IAppBuilder app, ClaimsTransformationOptions options)
        {
            if (options == null)
                throw new ArgumentNullException("options");

            app.Use(typeof(ClaimsTransformationMiddleware), options);
            return app;
        }
 public ClaimsTransformationMiddleware(Func<IDictionary<string, object>, Task> next, ClaimsTransformationOptions options)
 {
     _next = next;
     _options = options;
 }