public void TestGetHashCode_valuetype()
{
MyStruct s = new MyStruct();
s.SetMsg("Hello");
s.ID = 1;
s.Birthday = new DateTime(1981, 1, 1);
Console.WriteLine(s.GetHashCode());
Console.WriteLine(s.GetMsg().GetHashCode());
//s.SetMsg("NewMsg");
s.ID = 2;
s.Birthday = new DateTime(1981, 11, 11);
Console.WriteLine(s.GetHashCode());
Console.WriteLine(s.GetMsg().GetHashCode());
MyStruct s2 = new MyStruct();
s2.SetMsg(s.GetMsg());
s2.ID = 3;
Assert.AreEqual(s.GetHashCode(), s2.GetHashCode());
}