code: def _find_config_file(self):
          
          log.info("Searching for config in: {0}".format(
              ", ".join(str(p) for p in self._config_paths)))
  
          for cp in self._config_paths:
              f = self._search_in_path(cp)
              if f != "":
                  return f
  
          raise errors.ConfigFileNotFoundError(
              self._config_name, self._config_paths)
docs: Search all `config_paths` for any config file.
          Returns the first path that exists (and is a config file).