Analyze the operating principle of Laravel event system

protected $listen = [
        Registered::class => [
            SendEmailVerificationNotification::class,
        ],
        'App\Events\Test' => [
            'App\Listeners\EventListener',
        ],
    ];

$ php artisan event:generate

<?php

namespace App\Events;use App\Models\User;use Illuminate\Broadcasting\Channel;use Illuminate\Broadcasting\InteractsWithSockets;use Illuminate\Broadcasting\PresenceChannel;use Illuminate\Broadcasting\PrivateChannel;use Illuminate\Contracts\Broadcasting\ShouldBroadcast;use Illuminate\Foundation\Events\Dispatchable;use Illuminate\Queue\SerializesModels;class Test{
  use Dispatchable, InteractsWithSockets, SerializesModels;

  /**
 * Create a new event instance. * * @return void
 */  public function __construct($id)
 {  
     echo &#39;触发事件成功！---------&#39;.$id;
     $this->id = $id;
  }

  /**
 * Get the channels the event should broadcast on. * * @return \Illuminate\Broadcasting\Channel|array
 */  public function broadcastOn()
 {  return new PrivateChannel('channel-name');
  }}

<?php

namespace App\Listeners;
use App\Events\Test;use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Queue\InteractsWithQueue;
class EventListener{
  /**
 * Create the event listener. * * @return void
 */  public function __construct()
 {  //
  }

  public function handle(Test $event)
 {  
     echo &#39;监听成功！监听值：&#39;.$event->id;
 }}

public function test1(){
 event(new Test('11111111'));
 return '测试事件系统';}

php artisan event:generate
php artisan make:event UserRegisteredEvent
php artisan make:listener SendMailListener --event="UserRegisteredEvent"