public void TestTurnAround()
        {
            // Nord-Süd
            {
                Marcher4 marcher = new Marcher4(Door4.North, 0, 0);
                Assert.AreEqual(Door4.North, marcher.Direction);

                marcher.TurnAround();
                Assert.AreEqual(Door4.South, marcher.Direction);

                marcher.TurnAround();
                Assert.AreEqual(Door4.North, marcher.Direction);
            }

            // Ost-West
            {
                Marcher4 marcher = new Marcher4(Door4.West, 0, 0);
                Assert.AreEqual(Door4.West, marcher.Direction);

                marcher.TurnAround();
                Assert.AreEqual(Door4.East, marcher.Direction);

                marcher.TurnAround();
                Assert.AreEqual(Door4.West, marcher.Direction);
            }
        }
        public void TestTurnRight()
        {
            Marcher4 marcher = new Marcher4(Door4.North, 0, 0);
            Assert.AreEqual(Door4.North, marcher.Direction);

            Assert.AreEqual(Door4.East, marcher.RightDirection);
            marcher.TurnRight();
            Assert.AreEqual(Door4.East, marcher.Direction);

            Assert.AreEqual(Door4.South, marcher.RightDirection);
            marcher.TurnRight();
            Assert.AreEqual(Door4.South, marcher.Direction);

            Assert.AreEqual(Door4.West, marcher.RightDirection);
            marcher.TurnRight();
            Assert.AreEqual(Door4.West, marcher.Direction);

            Assert.AreEqual(Door4.North, marcher.RightDirection);
            marcher.TurnRight();
            Assert.AreEqual(Door4.North, marcher.Direction);
        }