protected override void OnPageEncountered(Uri url, System.Collections.Generic.IDictionary <string, string> query, System.Collections.Generic.IDictionary <string, string> fragment)
    {
        // Remove state from dictionaries.
        // We are ignoring request state forgery status
        // as we're hitting an ASP.NET service which forwards
        // to a third-party OAuth service itself
        if (query.ContainsKey("state"))
        {
            query.Remove("state");
        }

        if (fragment.ContainsKey("state"))
        {
            fragment.Remove("state");
        }

        base.OnPageEncountered(url, query, fragment);
    }