__clone makes it deep

1<?php2class Address3{4    public function __construct(public string $city) {}5}6class User7{8    public function __construct(public string $name, public Address $address) {}9 10    public function __clone(): void11    {12        $this->address = clone $this->address;13    }14}15$u1 = new User('Ann', new Address('Oslo'));16$u2 = clone $u1;17$u2->address->city = 'Rome';18echo $u1->name, ' ', $u1->address->city, PHP_EOL;19echo $u2->name, ' ', $u2->address->city, PHP_EOL;