code: public function setHeadDescription(string $description) : self
      {
          if (!$this->headDescription) {
              $this->headDescription = new HtmlElement('<meta>');
              $this->headDescription->addAttribute('name', 'description');
              $this->head->add($this->headDescription);
          }
          $this->headDescription->addAttribute('content', $description);
  
          return $this;
      }
docs: @param string $description
  
  @return $this|self