public void test_rererence()
        {
            copyConstructor cb1 = new copyConstructor(10);

            cb1.Display();
            copyConstructor cb2 = new copyConstructor(cb1);

            Assert.False(object.ReferenceEquals(cb1, cb2));
        }
 public copyConstructor(copyConstructor obj)
 {
     x = obj.x;
 }