Code snippet missing in Writing QML Extensions with C++ tutorial

I'm not sure without looking into the source of documentation (and that's quite tedious on its own), but this could be either a trolling on purpose, or just a bug. Seems like documentation on "Writing QML Extensions with C++" in Chapter 6 suggests using nocode implementation for the ChartsPlugin.

If that's intentional, then please make it clear by stating explicitly that such plugin class does not require .cpp counterpart.