public static OlaMundoSingleton getInstance()
{
if (_instance == null)
{
_instance = new OlaMundoSingleton();
}
return(_instance);
}
static void Main(string[] args)
{
//Console.WriteLine("Olá Mundo");
var factory = OlaMundoSingleton.getInstance().getFactory();
var sub = factory.createSubject();
sub.attach(factory.createObserver());
var cmd = factory.createCommand(sub);
cmd.execute();
}