public void TransposeShouldWork()
{
var t = new[] { new[] { 1, 2, 3 }, new[] { 4, 5, 6 }, new[] { 7, 8, 9 } };
var r = t.Transpose().Select(v => v.ToList()).ToList();
r[0].Should().Equal(1, 4, 7);
r[1].Should().Equal(2, 5, 8);
r[2].Should().Equal(3, 6, 9);
r.Count.Should().Be(3);
}