code: func validateAuthzPlugins(requestedPlugins []string, pg plugingetter.PluginGetter) error {
  	for _, reqPlugin := range requestedPlugins {
  		if _, err := pg.Get(reqPlugin, authorization.AuthZApiImplements, plugingetter.Lookup); err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // validates that the plugins requested with the --authorization-plugin flag are valid AuthzDriver
  // plugins present on the host and available to the daemon