The mutual authentication content is advanced material, therefore it belongs in the second volume of the tutorial where advanced topics are covered not in the first volume, which cover basic concepts. Content that covers how to create client certificates needs to be moved from the first to the second volume as well. To this, new sections that explain how to create server certificates, add certificates to keystores and truststores, and otherwise manipulate certificates needs to be added as well. Finally, an example needs to be created and documented in a second advanced security chapter in the second volume. This will show how to implement mutual authentication in a real example. The shopping cart in Duke's Bookstore where this security mechanism needs to be implemented.