Don't Try this

bad_oop.php

<?php
// https://twitter.com/timacdonald87/status/1615918480976662529/photo/1

class Foo
{
    static function bar()
    {
        return Bar::class;
    }
}

class Bar
{
    static $bar = Baz::class;
}

class Baz
{
    const qux = Qux::class;
}

class Qux
{
    public static function  quuz()
    {
        return Quuz::class;
    }
}


echo Foo::bar()::$bar::qux::quuz();

// Quuz%

// Notes: It doesn't actually execute the final class,
// it just reads it as a string as it's `ClassName::class`.

return_references.php

<?php

// https://www.php.net/manual/en/language.references.return.php
// https://twitter.com/timacdonald87/status/1615886928943153153

class MyList{
    private $list = [];
    function &getList(){
        return $this->list;
    }
    function add($item){
        $this->list[] = $item;
    }
}

$list = new MyList();
$list->add(1);
$list->add(2);

$arr = &$list->getList();
$arr[] = 3;
$arr[] = 4;

print_r($list->getList());