code: def _GenApiConfigCallback(args, api_func=GenApiConfig):
    
    service_configs = api_func(args.service,
                               hostname=args.hostname,
                               application_path=args.application)
  
    for api_name_version, config in service_configs.iteritems():
      _WriteFile(args.output, api_name_version + '.api', config)
docs: Generate an api file.
  
    Args:
      args: An argparse.Namespace object to extract parameters from.
      api_func: A function that generates and returns an API configuration
        for a list of services.