code: def update_paired_notebooks(self, path, fmt, formats):
          
          if not formats:
              self.drop_paired_notebook(path)
              return
  
          new_paired_paths = paired_paths(path, fmt, formats)
          for alt_path, _ in new_paired_paths:
              self.drop_paired_notebook(alt_path)
  
          long_formats = long_form_multiple_formats(formats)
          if len(long_formats) == 1 and set(long_formats[0]) <= {'extension'}:
              return
  
          short_formats = short_form_multiple_formats(formats)
          for alt_path, alt_fmt in new_paired_paths:
              self.paired_notebooks[alt_path] = short_form_one_format(alt_fmt), short_formats
docs: Update the list of paired notebooks to include/update the current pair