bool checkExsitColumn(List <Pairing> columnPool, Pairing path)
        {
            bool isExsit = false;

            for (int i = columnPool.Count - 1; i >= 0; i--)
            {
                if (path.equals(columnPool[i]))
                {
                    isExsit = true;
                    break;
                }
            }
            return(isExsit);
        }