void LoadTopScores(string leaderboardCode, IResultCallback callback)
        {
            var pendingResult = GamesClass.Leaderboards.LoadTopScores(_client, leaderboardCode, 2, 0, 25);

            pendingResult.SetResultCallback(callback);
        }
        void LoadAchievements(IResultCallback callback)
        {
            var pendingResult = GamesClass.Achievements.Load(_client, false);

            pendingResult.SetResultCallback(callback);
        }