in chapter07 on page 187 you talk in the text about predict_proba()
however in the source code of the notebook you directly then use predict()

after reading the whole paragraph the intention becomes then clear, however in the first place it is a bit irritating.
Maybe you can describe shortly both semantics and the approach to first find out which class (via predict()) and then detail each class (with the predcit_proba) method.

predict() is used to predict the actual class
predict_proba() is used to predict the class probabilities