public int CompareTo(object value)
        {
            if (value == null)
            {
                return 1;
            }
            if (!(value is string))
            {
                throw new ArgumentException("string degil");
            }
            return CustomCompare(this, (string) value);
        }

        public static int CustomCompare(string strA, string strB)
        {
            if (strA == strB)
            {
                return 0;
            }
            if (strA == null)
            {
                return -1;
            }
            if (strB == null)
            {
                return 1;
            }     
            throw new NotSupportedException("destek yok ?");
        }