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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():
 """Main entry."""

    parser = argparse.ArgumentParser()
    parser.add_argument("--host", type=str, required=True)
    parser.add_argument("--user", type=str, required=True)
    parser.add_argument("--password", type=str)
    parser.add_argument("--token", type=str)
    args = parser.parse_args()
    if not args.password and not args.token:
        print('password or token is required')
        exit(1)
    example(args.host, args.user, args.password, args.token)