public void TestThatSetLocationReturnsLocation()
            {
                MotionSensor sensor = new MotionSensor();

                sensor.SetLocation("Main Door");
                Assert.AreEqual("Main Door", sensor.GetLocation());
                sensor.SetLocation("I have changed...change is inevitable");
                Assert.AreNotEqual("Main Door", sensor.GetLocation());
            }
            public void TestThatGetLocationReturnsNull()
            {
                MotionSensor sensor   = new MotionSensor();
                string       location = sensor.GetLocation();

                Assert.AreEqual(string.Empty, location);
            }
            public void TestThatGetLocationReturnsLocation()
            {
                MotionSensor sensor   = new MotionSensor("Main Door");
                string       location = sensor.GetLocation();

                Assert.AreEqual("Main Door", location);
                MotionSensor sensor_2   = new MotionSensor("Back Door");
                string       location_2 = sensor_2.GetLocation();

                Assert.AreEqual("Back Door", location_2);
            }