name = $name; $this->age = $age; $this->addresses = array(); $this->secret = "$name confidential info"; } public function addAddress(Address $address) { $this->addresses[] = $address; } public function addFriend(Person $friend) { $this->friends[] = $friend; } public function bsonSerialize(): array { return array( "name" => $this->name, "age" => $this->age, "addresses" => $this->addresses, "friends" => $this->friends, ); } public function bsonUnserialize(array $data): void { $this->name = $data["name"]; $this->age = $data["age"]; $this->addresses = $data["addresses"]; $this->friends = $data["friends"]; } } class Address implements MongoDB\BSON\Persistable { protected $zip; protected $country; public function __construct($zip, $country) { $this->zip = $zip; $this->country = $country; } public function bsonSerialize(): array { return array( "zip" => $this->zip, "country" => $this->country, ); } public function bsonUnserialize(array $data): void { $this->zip = $data["zip"]; $this->country = $data["country"]; } }