code: def parser(subparsers):
      "Build an argparse argument parser to parse the command line."
  
      # create the parser for the version subcommand.
      parser_version = subparsers.add_parser(
          'version',
          help="Output the version of %(prog)s to the console.")
      parser_version.set_defaults(func=command_version)
  
      return parser_versiof parser(subparsers):
      "Build an argparse argument parser to parse the command line."
  
      # create the parser for the version subcommand.
      parser_version = subparsers.add_parser(
          'version',
          help="Output the version of %(prog)s to the console.")
      parser_version.set_defaults(func=command_version)
  
      return parser_version
docs: Build an argparse argument parser to parse the command line.