public override StockRatio ParseRatio(string s)
        {
            if (s.Length != 4)
            {
                throw new ArgumentException();
            }

            StockRatio ratio = new StockRatio();
            char[] arr = s.ToCharArray();

            ratio.RiseRatio = CharToRatio(arr[0]);

            ratio.UpRatio = CharToRatio(arr[1]);

            ratio.MaxRatio = CharToRatio(arr[2]);

            ratio.MinRatio = CharToRatio(arr[3]);

            return ratio;
        }
        public override StockRatio ParseRatio(string s)
        {
            if (s.Length != 4)
            {
                throw new ArgumentException();
            }

            StockRatio ratio = new StockRatio();

            char[] arr = s.ToCharArray();

            ratio.RiseRatio = CharToRatio(arr[0]);

            ratio.UpRatio = CharToRatio(arr[1]);

            ratio.MaxRatio = CharToRatio(arr[2]);

            ratio.MinRatio = CharToRatio(arr[3]);

            return(ratio);
        }