docs: def _pipe_line_with_colons(colwidths, colaligns):
      """Return a horizontal line with optional colons to indicate column's
      alignment (as in `pipe` output format)."""
      segments = [_pipe_segment_with_colons(a, w) for a, w in zip(colaligns, colwidths)]
      return "|" + "|".join(segments) + "|"