public void Start()
{
logger.Info("Mallard Duck:");
DuckHelper(new MallardDuck());
logger.Info("Spaniel Duck:");
DuckHelper(new SpanielDuck());
logger.Info("Customized Duck:");
var customizedDuck = new MallardDuck();
customizedDuck.SetFly(new FlyHigh());
DuckHelper(new MallardDuck());
}