Magic Method __sleep() and __wakeup()

index.php

<?php 

class Connection {
	protected $link;
	private $dsn, $username, $password;

	public function __construct($dsn, $username, $password) {
		$this->dsn = $dsn;
		$this->username = $username;
		$this->pasword = $password;
		$this->connect();
	}

	private function connect() {
		$this->link = new PDO($this->dsn, $this->username, $this->password);
	}

	private function disconnect() {
		unset($this->link);
	}

	public function __sleep() {
		echo "It's time to sleep! <br>";
		$this->disconnect();
		return ['dsn', 'username', 'password'];

	}

	public function __wakeup() {
		echo "It's time to wake up! <br>";
		$this->connect();
	}
}

$connection = new Connection("mysql:host=localhost;dbname=wpa26data", "root", "");

$con = serialize($connection);
var_dump($con);
unserialize($con);


?>