code: def is_dir_url(link):
      # type: (Link) -> bool
      
      link_path = url_to_path(link.url_without_fragment)
      return os.path.isdir(link_path)
docs: Return whether a file:// Link points to a directory.
  
      ``link`` must not have any other scheme but file://. Call is_file_url()
      first.