public void CheckThatHashCodesForDifferentDoubleEdgedPipeAreDifferent()
        {
            var pipe1 = new DoubleEdgedPipe(EdgeType.LEFT, EdgeType.UP);
            var pipe2 = new DoubleEdgedPipe(EdgeType.UP, EdgeType.DOWN);

            Assert.AreNotEqual(pipe1.GetHashCode(), pipe2.GetHashCode());
        }
        public void CheckThatHashCodesForSameDoubleEdgedPipeAreEqual()
        {
            var pipe1 = new DoubleEdgedPipe(EdgeType.DOWN, EdgeType.UP);
            var pipe2 = new DoubleEdgedPipe(EdgeType.UP, EdgeType.DOWN);

            Assert.AreEqual(pipe1.GetHashCode(), pipe2.GetHashCode());
        }