code: def _parse_option(line):
      
      match = _OPTION_REGEX.match(line)
      if not match:
          raise ValueError('Invalid syntax')
      for name, type_ in _OPTIONS:
          if name == match.group(1):
              return name, type_(match.group(2))
      raise ValueError('Unknown option')
docs: Parses option line.
      Returns (name, value).
      Raises ValueError on invalid syntax or unknown option.