he second argument. :param callable tuple_factory: A callable to produce tuples from. For example, to produce lists instead of tuples. :param bool retain_collection_types: Do not convert to ``list`` or ``dict`` when encountering an attribute which type is ``tuple``, ``dict`` or ``set``. Only meaningful if ``recurse`` is ``True``. :rtype: return type of *tuple_factory* :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` class. .. versionadded:: 16.2.0 NTŠ