public void DecoyDuck_Should_Not_Fly_Quack()
        {
            var decoyDuck = new DecoycDuck();

            Assert.Equal(String.Empty, decoyDuck.PerformQuack());
            Assert.Equal(string.Empty, decoyDuck.PerformFly());
        }
        public void DecoyDuck_Should_Swim_Display()
        {
            var decoyDuck = new DecoycDuck();

            Assert.Equal("swim", decoyDuck.Swim());
            Assert.Equal("looks like a decoyduck", decoyDuck.Display());
        }