Description:
------------
$dog->database->insert(); ////WHY THIS WORKS? "database" beeing a protected variable in Model class

Test script:
---------------
<?php
    final class Database {
        public $connection = "database connection stream";
        public function insert () {
            echo "inserted\n";
        }
    }

    abstract class Model {
        protected $database = null;
        public function __construct () {
            $this->database = new Database();
        }
    }
    
    class Dog extends Model {
        public function __construct () {
            parent::__construct();
        }
    }

    class Cat extends Model {
        public function testProtected() {
            $dog = new Dog();
            $dog->database->insert(); ////WHY THIS WORKS? "database" beeing a protected variable in Model class
        }
    }
    
    $cat = new Cat();
    $cat->testProtected();
?>

Expected result:
----------------
I expect that $dog->database->insert(); gives me "Cannot access protected property Dog::$database

Actual result:
--------------
it works for some reason.