Canine polymorphism example for blog post.

Canines.cs

public enum Food { Biscuit, Meatballs, You }

public interface ICanine
{
  string Bark { get; }

  bool Eats(Food f);
}

public class Wolf : ICanine
{
  public virtual string Bark { get { return "Aooo!"; } }

   public bool Eats(Food f) { return f != Food.Biscuit; }
}

public class Dog : ICanine
{
  public virtual string Bark { get { return "Woof!";  } }

  public virtual bool Eats(Food f) { return f != Food.You; }
}

public class Chihuahua : Dog
{
  public override string Bark { get { return "Arff!"; } }

  public override bool Eats(Food f) { return f == Food.Biscuit; }
}