scratch_2.php

<?php

class ObjectStorage {
    public $pairs = [];

    public function add(object $objectKey, $value): void
    {
        $this->pairs[] = [$objectKey, $value];
    }

    public function has(object $object): bool
    {
        return (bool) $this->get($object);
    }

    public function get(object $object)
    {
        foreach ($this->pairs as $pair) {
            if ($pair[0] === $object) {
                return $object;
            }
        }

        return null;
    }
}