// Core algorithm of building concrete products and thus // building composite product lies here Car* getCar() { Car* car = new Car(); car->body = builder->getBody(); car->engine = builder->getEngine(); car->wheels[0] = builder->getWheel(); car->wheels[1] = builder->getWheel(); car->wheels[2] = builder->getWheel(); car->wheels[3] = builder->getWheel(); return car; }