static void Main(string[] args)
        {
            Console.WriteLine("***** Custom Person Collection *****\n");
            PeopleCollection myPeople = new PeopleCollection();

            myPeople.AddPerson(new Person("Homer", "Simpson", 40));
            myPeople.AddPerson(new Person("Marge", "Simpson", 38));
            myPeople.AddPerson(new Person("Lisa", "Simpson", 9));
            myPeople.AddPerson(new Person("Bart", "Simpson", 7));
            myPeople.AddPerson(new Person("Maggie", "Simpson", 2));

            // This would be a compile-time error!
            // myPeople.AddPerson(new Car());

            foreach (Person p in myPeople)
            {
                Console.WriteLine(p);
            }
            Console.ReadLine();
        }