public int CompareTo(ValX1 <T> obj)
        {
            if (_val == null)
            {
                if (obj._val == null)
                {
                    return(0);
                }

                return(-1);
            }
            return(_val.CompareTo(obj._val));
        }
 public bool Equals(ValX1 <T> obj)
 {
     return(0 == CompareTo(obj));
 }