public void Accelerate_ShouldDownshiftAndNotMakeSound_WhenCurrentRpmIsLesserThanDownshiftBoundary() { var currentRpm = new Rpm(1000d); _externalSystems.GetCurrentRpm().Returns(currentRpm); var shiftBoundaries = GetShiftBoundaries(1500d, 3000d); Sut().Accelerate(shiftBoundaries); _gearShifter.Received().Downshift(); _gearShifter.DidNotReceive().Upshift(); _externalSystems.DidNotReceive().MakeSound(Arg.Any <SoundVolume>()); }