code: public function update($previousPermalink, $newPermalink)
      {
          $blocks = $this->permalinks[$previousPermalink];
          $this->remove($previousPermalink);
          $this->permalinks[$newPermalink] = $blocks;
  
          return $this;
      }
docs: Updates a permalink
  
  @param $previousPermalink
  @param $newPermalink
  
  @return $this