Create instance of me!

Dog.php

<?php

class Dog {

    private $dog;

    public function __construct(Dog $dog)
    {
        $this->dog = $dog;
    }

    public function getDog()
    {
        return $this->dog;
    }
}

$reflection = new ReflectionClass(Dog::class);

$dog = $reflection->newInstanceWithoutConstructor();

$property = $reflection->getProperty('dog');
$property->setAccessible(true);
$property->setValue($dog, $dog);

var_dump($dog);
var_dump($dog->getDog());
var_dump($dog === $dog);