Laravel: How to create custom model events

Address.php

<?php

// App\Address Model

namespace App;

use Illuminate\Database\Eloquent\Model;
use App\Observers\AddressObserver; // included our Model Observer

/**
 * Class Address
 * @package app
 */
class Address extends Model
{

    /**
    * Array of our custom model events declared under model property $observables
    * @var array
    */
  
    protected $observables = [
        'published',
        'unpublished',
    ];
  
  
  /**
  * Publish address & fire custom model event
  *
  */
  public function publish()
  {
    
    // logic to update Address status goes here
    
    // fire custom event on the model
    $this->fireModelEvent('published', false);
    
  }
  
  /**
  * Unpublish address & fire custom model event
  *
  */
  public function unPublish()
  {
    
    // logic to update Address status goes here
    
    // fire custom event on the model
    $this->fireModelEvent('unpublished', false);
    
  }
  
  
}
?>

AddressObserver.php

<?php

// App\Observers

namespace App\Observers;

use App\Address;  // model included to have access to data
use Illuminate\Support\Facades\Log; // Log included to log info

class AddressObserver
{

    /**
     * @param Address $address
     */

    public function published(Address $address)
    {
      
      // I am testing here by logging info into logs, you can do anything here,
      // like send emails, insert into database, or notify via sms,
      // all logic goes here
      
      Log::info('Address is published ('.$address->name.')');
      
    }

  
  /**
     * @param Address $address
     */

    public function unpublished(Address $address)
    {
      
      // logic goes here
      
    }

}

AppServiceProvider.php

<?php

// App\Providers

namespace App\Providers;

use App\Address; // model
use App\Observers\AddressObserver; // model observer
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
      
      // https://laravel.com/docs/5.4/eloquent#observers
      // observer to group listeners into a single class,
      
      Address::observe(AddressObserver::class); 
    }

    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        //
    }
}