private static void Main(string[] args)
{
    Person father = new Person();
    Person mother = new Person();
    Person girl = new Person();
 
    Person boy = mother.Emit(mother.Union(father),
        new DateTime(2007, 4, 21));
    girl.PromoteTo(Rank.BigSister);
 
    mother.Condition = Conditions.Well | Conditions.Tired;
    father.Condition = Conditions.Well | Conditions.Tired;
    boy.Condition = Conditions.Well;
    girl.Condition = Conditions.Happy;
 
    Console.WriteLine(boy.ToString());
}