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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(argv=None):
 """Run dvc CLI command. Args: argv: optional list of arguments to parse. sys.argv is used by default. Returns: int: command's return code. """

    args = None
    cmd = None

    try:
        args = parse_args(argv)

        if args.quiet:
            logger.setLevel(logging.CRITICAL)

        elif args.verbose:
            logger.setLevel(logging.DEBUG)

        cmd = args.func(args)
        ret = cmd.run_cmd()
    except KeyboardInterrupt:
        logger.exception("interrupted by the user")
        ret = 252
    except NotDvcRepoError:
        logger.exception("")
        ret = 253
    except DvcParserError:
        ret = 254
    except Exception:  # pylint: disable=broad-except
        logger.exception("unexpected error")
        ret = 255

    Analytics().send_cmd(cmd, args, ret)

    return ret