docs: def _shorten_render(renderer, max_len):
      """Return a modified that returns the representation of expr, or '...' if
      that representation is longer than `max_len`"""
  
      def short_renderer(expr):
          res = renderer(expr)
          if len(res) > max_len:
              return '...'
          else:
              return res
  
      return short_renderer