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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 main(dialogpath=None):
 """ Parse the state transition graph for a set of dialog-definition tables to find an fix deadends """

    if dialogpath is None:
        args = parse_args()
        dialogpath = os.path.abspath(os.path.expanduser(args.dialogpath))
    else:
        dialogpath = os.path.abspath(os.path.expanduser(args.dialogpath))
    return clean_csvs(dialogpath=dialogpath)