human
Here's a good function header given the following:
I wrote the below code

    def _FakeRetrying(wait_func=None, original_retrying=driver.utils.retrying.Retrying, *args, **kwargs):
        return original_retrying(wait_func=(lambda *a, **k: 0), *args, **kwargs)
    def _common_inner_inner1(inst, *args, **kwargs):
        @mock.patch('retrying.Retrying', _FakeRetrying)
        @mock.patch.object(driver.RBDDriver, '_get_usage_info')
        @mock.patch('cinder.volume.drivers.rbd.RBDVolumeProxy')
        @mock.patch('cinder.volume.drivers.rbd.RADOSClient')
        @mock.patch('cinder.backup.drivers.ceph.rbd')
        @mock.patch('cinder.backup.drivers.ceph.rados')
        def _common_inner_inner2(mock_rados, mock_rbd, mock_client, mock_proxy, mock_usage_info):
            inst.mock_rbd = mock_rbd
            inst.mock_rados = mock_rados
            inst.mock_client = mock_client
            inst.mock_proxy = mock_proxy
            inst.mock_rbd.RBD.Error = Exception
            inst.mock_rados.Error = Exception
            inst.mock_rbd.ImageBusy = MockImageBusyException
            inst.mock_rbd.ImageNotFound = MockImageNotFoundException
            inst.mock_rbd.ImageExists = MockImageExistsException
            inst.mock_rbd.InvalidArgument = MockImageNotFoundException
            inst.driver.rbd = inst.mock_rbd
            inst.driver.rados = inst.mock_rados
            return f(inst, *args, **kwargs)
        return _common_inner_inner2()
    return _common_inner_inner1

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

def common_mocks(f):