public void TestThatGetSensorTypeReturnsNull()
            {
                MotionSensor sensor     = new MotionSensor();
                string       sensorType = sensor.GetSensorType();

                Assert.AreNotEqual(string.Empty, sensorType);
            }
            public void TestThatGetSensorTypeReturnsType()
            {
                MotionSensor sensor     = new MotionSensor();
                string       sensorType = sensor.GetSensorType();

                Assert.AreEqual("Motion sensor", sensorType);
            }