Untitled

<?php

class MySQLDatabase {
    public function saveOrder($order) {
        // Logic to save the order in MySQL database
        echo "Saving order to MySQL database.\n";
    }
}

class OrderService {
    private $db;

    public function __construct() {
        $this->db = new MySQLDatabase(); // Direct dependency on a specific implementation
    }

    public function placeOrder($order) {
        // Some logic for placing the order
        $this->db->saveOrder($order);
    }
}

// Usage
$orderService = new OrderService();
$orderService->placeOrder('Order 1');