public static IAppBuilder UseOAuth2CodeRedeemer(this IAppBuilder app, OAuth2CodeRedeemerOptions options)
 {
     app.Use <OAuth2CodeRedeemerMiddleware>(options);
     return(app);
 }
 public OAuth2CodeRedeemerMiddleware(OwinMiddleware next, OAuth2CodeRedeemerOptions options)
     : base(next)
 {
     this.options = options ?? throw new ArgumentNullException("options");
 }