void AssignAnimal()
        {
            Animals animals = null;

            Console.WriteLine("Choose the animal horse or donkey");
            string Choice = Console.ReadLine().ToUpper();

            switch (Choice)
            {
            case "HORSE":
                animals = new Horse();
                break;

            case "DONKEY":
                animals = new Donkey();
                break;

            default:
                Console.WriteLine();
                break;
            }
            pullCart(animals);
        }
 void pullCart(Animals animals)
 {
     animals.Eat();
     animals.sleep();
     animals.Move();
 }