Hello, Would @chrisconlan, or the community please confirm that the charts in chapter 5 no longer match the images in the book please? I get these when running on windows in jupyter notebook in vscode: excess_cagr (this one is good)  bollinger_n does not match what's in the book:  and the 3d bollinger_n/sharpe_n chart does not render at all:  Is there a bug in the book or code or did python evolve and expects different code? Thank you.