def METHOD_NAME(self):
    input = InputCell(1)
    plus_one = ComputeCell(
        [
            input,
        ],
        lambda inputs: inputs[0] + 1,
    )
    minus_one = ComputeCell(
        [
            input,
        ],
        lambda inputs: inputs[0] - 1,
    )
    cb1_observer = []
    cb2_observer = []
    callback1 = self.callback_factory(cb1_observer)
    callback2 = self.callback_factory(cb2_observer)
    plus_one.add_callback(callback1)
    minus_one.add_callback(callback2)
    input.value = 10
    self.assertEqual(cb1_observer[-1], 11)
    self.assertEqual(cb2_observer[-1], 9)