human
I wrote the below code

    class metaclass(meta, ):
        __call__ = type.__call__
        __init__ = type.__init__
        def __new__(cls, name, nbases, d):
            if (nbases is None):
                return type.__new__(cls, name, (), d)
            if ((not PY3) and ('___metaclass__' not in d)):
                d['__metaclass__'] = meta
            return meta(name, bases, d)
    return metaclass((meta.__name__ + 'Helper'), None, {})

What's a good function header?
assistant
#Here's a good function header.

def with_metaclass(meta, *bases):