// Main Method
        public static void Main(String[] args)
        {
            // creating an instance of Bicycle
            Bicycle bicycle = new Bicycle();

            // Creating interface references
            Vehicle obj;

            // assigning Bicycle object 'bicycle'
            // to interface Reference 'obj'
            obj = bicycle;

            // calling the abstract methods
            // implemented by class Bicycle
            obj.changeGear(4);
            obj.speedUp(5);
            obj.applyBrakes(2);

            Console.WriteLine("Bicycle Present State:");

            // calling the method of class Bicycle
            obj.printStates();
        }
        public static void Main(String[] args)
        {
            // Instantiate the an object 'bicycle' using
            // the default constructor for the Bicycle class
            // The parameters for each method inside the class
            // are passed using literals
            Bicycle bicycle = new Bicycle();

            bicycle.ChangeGear(2);
            bicycle.SpeedUp(3);
            bicycle.ApplyBrakes(1);

            Console.WriteLine("Bicycle present state :");
            bicycle.printStates();

            Scooter scooter = new Scooter();

            scooter.ChangeGear(1);
            scooter.SpeedUp(4);
            scooter.ApplyBrakes(3);

            Console.WriteLine("Scooter present state :");
            scooter.printStates();
        }