def testLetBatteryCoolToTemperature_timeoutAfterThree(self):
    self.mock_device.ReadFile = mock.Mock(side_effect=self.constant_temp)
    self.cpu_temp.LetCpuCoolToTemperature(42)
    self.mock_device.ReadFile.assert_called()
    self.assertEquals(self.mock_device.ReadFile.call_count, 24)