public Cat(Animal friend) : this() { Friend = friend; }
public Duck(Animal friend, int age) : this() { Interlocked.Increment(ref CtorFriendAge); Age = age; Friend = friend; }
public Duck(Animal friend) : this() { Friend = friend; }
public Duck(int age, Animal friend) : this() { Interlocked.Increment(ref CtorAgeFriend); Age = age; Friend = friend; }
public Dog(Animal friend) : this() { Friend = friend; }