Unnamed

class A (object):    def __init__(self, aFoo, aBar, aBaz):        self._foo = aFoo        self._bar = aBar        self._baz = aBazclass B (A):    def __init__(self, aFoo=None, aBar=None, aBaz=None, aQuux=None, anA=None):        if anA is not None:            assert aFoo is aBar is aBaz is None            super(B, self).__init__(anA._foo, anA._bar, anA._baz)        else:            super(B, self).__init__(aFoo, aBar, aBaz)        self._quux = aQuux