I was having a play with the book's C# download code relating to build providers pages 87-93, chapter 3.
I have it all working fine however one thing is puzzling me. When I create my own solution and add a custom build provider in a class library, as described in the book, I find I need to add a reference to the class library. Now that is what I would expect, and it all works fine when I do so. What is a mystery to me is that the book's download code appears not to need this reference to work.
Furthermore, when a new class library is added to the book's download code and defines a new build provider, then a reference is needed for that new build provider to work while the original car build provider continues to works happily without one. I wonder if someone can tell me how the CarBuildProvider is being referenced and how that technique can be similarly applied to a new build provider class library.