code: def com_google_fonts_check_varfont_regular_opsz_coord(ttFont, regular_opsz_coord):
    
  
    if regular_opsz_coord >= 9 and regular_opsz_coord <= 13:
      yield PASS, ("Regular:opsz coordinate ({})"
                   " looks good.").format(regular_opsz_coord)
    else:
      yield WARN, ("The 'opsz' (Optical Size) coordinate"
                   " on the 'Regular' instance is recommended"
                   " to be a value in the range 9 to 13."
                   " Got a '{}' coordinate instead."
                   "").format(regular_opsz_coord)
docs: The variable font 'opsz' (Optical Size) axis coordinate should be between
    9 and 13 on the 'Regular' instance.