@_replaceIf(_PY3, passthru)
@_replaceIf(not _shouldEnableNewStyle(), _ensureOldClass)
def _oldStyle(cls):
    _ensureOldClass(cls)
    return type(cls.__name__, (object,), cls.__dict__)
A decorator which conditionally converts old-style classes to new-style
dataset/ETHPy150Open twisted/twisted/twisted/python/_oldstyle.py/_oldStyle