Flarum\Foundation\Application::booting PHP Метод

    public function booting($callback)
    {
        $this->bootingCallbacks[] = $callback;
    }

 public function subscribe(Dispatcher $events)
 {
     if (defined('FLARUM_TENANT')) {
         $events->listen(ConfigureClientView::class, [$this, 'setFilename']);
         Application::booting(function ($app) {
             $app->make('config')->set('cache.prefix', FLARUM_TENANT);
         });
     }
 }