public void HorizontalAppendTest()
        {
            BitMatrix matrix = new BitMatrix(new int[, ]
            {
                { 0, 1 },
                { 1, 0 }
            });

            BitMatrix identity = BitMatrix.Identity(2);

            BitMatrix merged = identity.AppendHorizontally(matrix);

            Assert.True(merged[0, 0]);
            Assert.True(merged[1, 1]);
            Assert.True(merged[1, 2]);
            Assert.True(merged[0, 3]);
        }