public override bool Equals(object obj)
            {
                ComparableClassEquals cc = (obj as ComparableClassEquals);

                if (cc == null)
                {
                    return(false);
                }

                return(x == cc.x);
            }
            public int CompareTo(object obj)
            {
                ComparableClassEquals cc = (obj as ComparableClassEquals);

                if (cc == null)
                {
                    throw new ArgumentException("wrong type", "obj");
                }

                return(x.CompareTo(cc.x));
            }