p. 219: "2. The WSGI server used by the repoze.bfg application passes the WSGI 
environment to the __call__ method of the repoze.bfg router object." Where does 
the __call__ method live inside the application itself?

This one thing is the only thing I have with a question mark next to it in the 
chapter. I have underlined it pretty heavily, and, laid out step-by-step like this, it 
makes quite a bit of sense, and is a generally good overview of the entire book. 
Even if there are a couple of things I don't understand, I underlined all of the 
important points of each paragraph, so I'll be able to refer back to that if I have any 
questions.