Laravel Dispatcher and payloads

Code
<?php

use Illuminate\Events\Dispatcher;

$dispatcher = new Dispatcher();

$eventListener = function (int $integerstring $string) {
    
dump($integer$string);
    echo 
'Hello Laravel' PHP_EOL;
};

// Add event listener
$dispatcher->listen('callme'$eventListener);

// fire event
$payload = [5'value'];
$dispatcher->fire('callme'$payload);
Result
5

"value"

Hello Laravel
Used Versions
PHP 7.1, Zend 3.0, Symfony 3.2, Laravel 5.2, PHPUnit 5.6, Doctrine 2.6