code: public function getUrl()
      {
          if (is_integer($this->focus)) {
              $url = $this->frames[$this->focus]->getUrl();
              $url->setTarget($this->getPublicNameFromIndex($this->focus));
          } else {
              $url = $this->frameset->getUrl();
          }
  
          return $url;
      }
docs: Original resource name.
  
  @return SimpleUrl        Current url.