'Test updating a group
should throw NotImplementedError, is_group_a_cg_snapshot_type=False
otherwise returns \'None\' for each of the updates'

@mock.patch('cinder.volume.utils.is_group_a_cg_snapshot_type')
def test_update_group(self, is_group_a_cg_snapshot_type):

    is_group_a_cg_snapshot_type.side_effect = [False, True]
    self.assertRaises(NotImplementedError, self.driver.update_group, self.ctx, self.group)
    (mod_up, add_up, remove_up) = self.driver.update_group(self.ctx, self.group)
    self.assertIsNone(mod_up)
    self.assertIsNone(add_up)
    self.assertIsNone(remove_up)
