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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 _add_baseline_to_exclude_files(args):
 """ Modifies args.exclude_files in-place. """

    baseline_name_regex = r'^{}$'.format(args.import_filename[0])

    if not args.exclude_files:
        args.exclude_files = baseline_name_regex
    elif baseline_name_regex not in args.exclude_files:
        args.exclude_files += r'|{}'.format(baseline_name_regex)