abstract class Creator
{
    abstract public function factoryMethod(): Product;
    public function someOperation(): string
    {
        $product = $this->factoryMethod();
        $result = "Creator: The same creator's code has just worked with " . $product->operation();
        return $result;
    }
}
class ConcreteCreator1 extends Creator
{
    public function factoryMethod(): Product
    {
        return new ConcreteProduct1();
    }
}
class ConcreteCreator2 extends Creator
{
    public function factoryMethod(): Product
    {
        return new ConcreteProduct2();
    }
}
interface Product
{
    public function operation(): string;
}
class ConcreteProduct1 implements Product
{
    public function operation(): string
    {
        return "{Result of the ConcreteProduct1}";
    }
}
class ConcreteProduct2 implements Product
{
    public function operation(): string
    {
        return "{Result of the ConcreteProduct2}";
    }
}
function clientCode(Creator $creator)
{
    echo "Client: I'm not aware of the creator's class, but it still works.\n" . $creator->someOperation() . "\n";
}
echo "App: Launched with the ConcreteCreator1.\n";
clientCode(new ConcreteCreator1());
echo "App: Launched with the ConcreteCreator2.\n";
clientCode(new ConcreteCreator2());