Set up the mocked Sensor in the test. But got error message 'System.N…

…otSupportedException : Invalid setup on a non-virtual (overridable in VB) member: s => s.PopNextPressurePsiValue()'. Will extract interface for class Sensor.

TDDMicroExercises.YoursSolutions/CSharp-benwu/TirePressureMonitoringSystem.Tests/AlarmTest.cs

@@ -16,6 +16,10 @@ public void WHEN_check_pressure_value_in_alarm_THEN_get_characterization_of_whet
             var sensor = new Mock<Sensor>();
             var alarm = new Alarm(sensor.Object);
 
+            sensor
+                .Setup(s => s.PopNextPressurePsiValue())
+                .Returns(16.0);
+
             // When
             alarm.Check();