public void TestValidToyRotateLeft()
        {
            // arrange
            var toyRobot = new ToyRobotPlacementService {
                Direction = ToyFacingDirectionEnum.West, Position = new ToyPosition(2, 1)
            };

            // act
            toyRobot.Rotate(ToyCommandEnum.Left);

            // assert
            Assert.AreEqual(ToyFacingDirectionEnum.North, toyRobot.Direction);
        }
        public void TestInValidToyRotateRight()
        {
            // arrange
            var toyRobot = new ToyRobotPlacementService {
                Direction = ToyFacingDirectionEnum.North, Position = new ToyPosition(3, 4)
            };

            // act
            toyRobot.Rotate(ToyCommandEnum.Right);

            // assert
            Assert.AreEqual(ToyFacingDirectionEnum.South, toyRobot.Direction);
        }