public void RectangularPanVolume2()
        {
            var        rect   = new RectangularPan(8, 11, 2);
            IGetVolume getVol = (IGetVolume)rect;
            var        actual = getVol.GetVolume();

            Assert.AreEqual(176, actual);
        }
        public void RectangularPanVolume()
        {
            var        rect   = new RectangularPan(9, 13, 2);
            IGetVolume getVol = (IGetVolume)rect;
            var        actual = getVol.GetVolume();

            Assert.AreEqual(234, actual);
        }