private static void Main()
{
var eSon = new EldestSon();
var mSon = new MiddleSon();
var ySon = new YoungestSon();
var dad = new Dad(eSon) { PSon = ySon };
const string message = "Help: ";
dad.Notify(message);
Dad.Notify(mSon, message);
DiUtils.WaitForKeyPress();
}
