code: def main():
      
      parser = argparse.ArgumentParser(
          description='Manage the build environment of Boost.Metaparse'
      )
      parser.add_argument(
          '--dep_json',
          required=True,
          help='The json file describing the dependencies'
      )
      parser.add_argument(
          '--git',
          required=False,
          default='git',
          help='The git command to use'
      )
      parser.add_argument(
          '--out',
          required=False,
          default='boost',
          help='The directory to clone into'
      )
      parser.add_argument(
          '--action',
          required=True,
          choices=['update', 'checkout'],
          help='The action to do with the dependencies'
      )
      parser.add_argument(
          '--boost_repository',
          required=False,
          default='https://github.com/boostorg/boost.git',
          help='The Boost repository to clone'
      )
      parser.add_argument(
          '--ref',
          required=False,
          default='origin/master',
          help='The reference to set to in update'
      )
      args = parser.parse_args()
  
      build_environment(
          args.dep_json,
          args.out,
          ChildProcess([args.git]),
          args.boost_repository,
          args.action,
          args.ref
      )
docs: The main function of the utility