code: def _require_min_api_version(self, version):
      
      actual_version = self._get_resource_root().version
      version = max(version, self._api_version())
      if actual_version < version:
        raise Exception("API version %s is required but %s is in use."
            % (version, actual_version))
docs: Raise an exception if the version of the api is less than the given version.
  
      @param version: The minimum required version.