public void mallard_duck_can_swim()
 {
     Duck mallard = new MallardDuck();
     Assert.AreEqual("All ducks float, even decoys!", mallard.Swim());
 }
 public void mallard_duck_can_fly()
 {
     Duck mallard = new MallardDuck();
     Assert.AreEqual("I'm flying!!", mallard.PerformFly());
 }
 public void mallard_duck_can_quack()
 {
     Duck mallard = new MallardDuck();
     Assert.AreEqual("Quack", mallard.PerformQuack());
 }
 public void duck_is_a_mallard_duck()
 {
     Duck mallard = new MallardDuck();
     Assert.AreEqual("I'm a Mallard Duck.", mallard.Display());
 }