@Test
public void testCustomQuackBehavior(){
//Given: A Redhead duck
//And: I want to change the quacking behavior at runtime from its default
//When: The quacking behavior is changed
redheadDuck.setQuackBehavior(new DemoMuteQuack());
//And: The Redhead duck is asked to quack
//Then: It should demonstrate the new correct quacking behavior
String expected = "...Really? I can't quack. Oddly I do seem to do Englsih pretty well.";
assertTrue(DuckTester.quackBehavior(redheadDuck, expected));
}