'The attributes that proxy objects proxy should be deletable and affect
the original object.'

def test_proxyDeleteAttribute(self):

    yayable = Yayable()
    yayable.ifaceAttribute = None
    proxy = proxyForInterface(IProxiedInterface)(yayable)
    del proxy.ifaceAttribute
    self.assertFalse(hasattr(yayable, 'ifaceAttribute'))
