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

            app.Use(typeof(BitbucketAuthenticationMiddleware), app, options);

            return app;
        }
        public static IAppBuilder UseBitbucketAuthentication(this IAppBuilder app,
                                                             BitbucketAuthenticationOptions options)
        {
            if (app == null)
            {
                throw new ArgumentNullException("app");
            }
            if (options == null)
            {
                throw new ArgumentNullException("options");
            }

            app.Use(typeof(BitbucketAuthenticationMiddleware), app, options);

            return(app);
        }