docs: def iter_settings(mixed: Settings) -> Iterator[Tuple[str, Any]]:
      """Iterate over settings values from settings module or dict-like instance.
  
      :param mixed: Settings instance to iterate.
      """
      if isinstance(mixed, types.ModuleType):
          for attr in dir(mixed):
              if not is_setting_key(attr):
                  continue
              yield (attr, getattr(mixed, attr))
      else:
          yield from filter(lambda item: is_setting_key(item[0]), mixed.items())