code: func importOSes(c context.Context, configSet config.Set) error {
  	os := &configPB.OSes{}
  	metadata := &config.Meta{}
  	if err := cfgclient.Get(c, cfgclient.AsService, configSet, osesFilename, textproto.Message(os), metadata); err != nil {
  		return errors.Annotate(err, "failed to load %s", osesFilename).Err()
  	}
  	logging.Infof(c, "Found %s revision %q", osesFilename, metadata.Revision)
  
  	ctx := &validation.Context{Context: c}
  	ctx.SetFile(osesFilename)
  	validateOSes(ctx, os)
  	if err := ctx.Finalize(); err != nil {
  		return errors.Annotate(err, "invalid config").Err()
  	}
  
  	if err := model.EnsureOSes(c, os.OperatingSystem); err != nil {
  		return errors.Annotate(err, "failed to ensure operating systems").Err()
  	}
  	return nil
  }
docs: // importOSes fetches, validates, and applies operating system configs.