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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def command_check(string, vargs):
 """ 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 """

    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)