public static void Demo()
{
var p1 = new PersonV1("Fred", "Flintstone");
GetMiddleNameLength(p1);
var p2 = new PersonV2("Barney", "Rubble");
GetMiddleNameLength(p2);
Weapon cantBeNull;
Weapon?canBeNull;
canBeNull = null;
// Note the compiler warning
cantBeNull = null;
canBeNull = new Weapon();
cantBeNull = new Weapon();
canBeNull.Repair();
cantBeNull.Repair();
}
// This works, but will fail public static int GetMiddleNameLength(PersonV1 p) => p.MiddleName.Length;
