code: def _validate_config(self, config):
          
          if config is None:
              raise ValueError("OIDCFrontend conf can't be 'None'.")
  
          for k in {"signing_key_path", "provider"}:
              if k not in config:
                  raise ValueError("Missing configuration parameter '{}' for OpenID Connect frontend.".format(k))
docs: Validates that all necessary config parameters are specified.
          :type config: dict[str, dict[str, Any] | str]
          :param config: the module config