'Calling constructor with empty instance id creates a different
id each time.'

def test_unique_instance_id_if_not_provided(self):

    a = LoopbackBlockDeviceAPI.from_path(root_path='')
    b = LoopbackBlockDeviceAPI.from_path(root_path='')
    self.assertNotEqual(a.compute_instance_id(), b.compute_instance_id())
