View file vendor/laravel/framework/src/Illuminate/Broadcasting/Broadcasters/NullBroadcaster.php

<?php

namespace Illuminate\Broadcasting\Broadcasters;

class NullBroadcaster extends Broadcaster
{
    /**
     * {@inheritdoc}
     */
    public function auth($request)
    {
        //
    }

    /**
     * {@inheritdoc}
     */
    public function validAuthenticationResponse($request, $result)
    {
        //
    }

    /**
     * {@inheritdoc}
     */
    public function broadcast(array $channels, $event, array $payload = [])
    {
        //
    }
}