Readable PHP

<?php

class ? {
    public $weight = 5;

    public function bark(): void {
        echo "woof";
    }

    public function eat(? $?): void {
        $this->weight += $?->weight;
    }
}

class ? {
    public $weight = 10;
}

$? = new ?();
$?->eat(new ?);
var_dump($?->weight);