public Flock()

        {

            observable = new Observable(this);

        }
        public DuckCall()

        {

            observable = new Observable(this);

        }
        public MallardDuck()

        {

            observable = new Observable(this);

        }
        public RubberDuck()

        {

            observable = new Observable(this);

        }
        public RedheadDuck()

        {

            observable = new Observable(this);

        }
        public QuackCounter(IQuackable duck)

        {

            this.duck = duck;

            observable = new Observable(this);

        }
        public GooseAdapter(Goose goose)

        {

            this.goose = goose;

            observable = new Observable(this);

        }