"target_system.erl" module is not included?

In section "Wrapping Up" of chapter 11:

> In doing so, the user’s guide introduces the target_system.erl module shipped in the sasl application’s examples directory as well as in this chapter’s directory in the book’s GitHub repository. 

Does it mean this repository included "target_system.erl" module in ch11 directory? But I didn't find it.

Thanks.

