code: def command_check(string, vargs):
      
      is_valid = is_valid_ipa(string)
      print(is_valid)
      if not is_valid:
          valid_chars, invalid_chars = remove_invalid_ipa_characters(
              unicode_string=string,
              return_invalid=True
          )
          print_invalid_chars(invalid_chars, vargs)
docs: Check if the given string is IPA valid.
  
      If the given string is not IPA valid,
      print the invalid characters.
  
      :param str string: the string to act upon
      :param dict vargs: the command line arguments