WPSEO_Features::is_premium PHP Method

    public function is_premium()
    {
        return defined('WPSEO_PREMIUM_FILE');
    }

 /**
  * Checks if the notice should be added or removed.
  */
 public function initialize()
 {
     $features = new WPSEO_Features();
     if ($features->is_premium() || $this->is_notice_dismissed()) {
         $this->remove_notification();
         return;
     }
     if ($this->should_add_notification()) {
         $this->add_notification();
     }
 }