Influence var_dump output of an object in PHP

Code
<?php

class Foo
{
    private 
$bar 'bar';
    
    public function 
__debugInfo()
    {
        return [
            
'notAProp' => 'this is not a property'
        
];
    }
}

var_dump(new Foo());
Result
object(Foo)#371 (1) {
["notAProp"]=>
string(22) "this is not a property"
}
Used Versions
PHP 7.1, Zend 3.0, Symfony 3.2, Laravel 5.2, PHPUnit 5.6, Doctrine 2.6