code: def Main():
    
    args_parser = argparse.ArgumentParser(
        description='Validates an artifact definitions file.')
  
    args_parser.add_argument(
        'filename',
        nargs='?',
        action='store',
        metavar='artifacts.yaml',
        default=None,
        help=('path of the file that contains the artifact '
              'definitions.'))
  
    options = args_parser.parse_args()
  
    if not options.filename:
      print('Source value is missing.')
      print('')
      args_parser.print_help()
      print('')
      return False
  
    if not os.path.isfile(options.filename):
      print('No such file: {0:s}'.format(options.filename))
      print('')
      return False
  
    print('Validating: {0:s}'.format(options.filename))
    validator = ArtifactDefinitionsValidator()
    if not validator.CheckFile(options.filename):
      print('FAILURE')
      return False
  
    print('SUCCESS')
    return True
docs: The main program function.
  
    Returns:
      bool: True if successful or False if not.