Guzzle4 subscribers for access_token

AccessTokenSubscriber.php

<?php

namespace Hpatoio\Bitly\Subscribers;

use GuzzleHttp\Event\EmitterInterface;
use GuzzleHttp\Event\SubscriberInterface;
use GuzzleHttp\Command\Event\PrepareEvent;

class AccessTokenSubscriber implements SubscriberInterface
{
    private $accessToken;
    
    public function __construct($accessToken) {
        $this->accessToken = $accessToken;
    }
    
    public function getEvents()
    {
        return [
            'prepare'   => ['onPrepare'],
        ];
    }

    public function onPrepare(PrepareEvent $event)
    {
        
        // AddParam method doesn't exist in the original version of GuzzleHttp\Command
        $event->getCommand()->addParam("access_token", $this->getAccessToken());

    }
    
    public function getAccessToken() {
        return $this->accessToken;
    }

}