TicTacToeGameUtil.TicTacToeGameBasic.GetPossiblePlays C# (CSharp) Method

        public List<int> GetPossiblePlays()

        {
            var allPlays = new List<int> { 1, 2, 3, 4, 5, 6, 7, 8, 9 };

            return allPlays.Except(AllGamePlays).ToList();
        }