Listing 6.5 and the Null Safety discussion

This is perhaps a quibble, but the null safety discussion on page 87 refers to attempting to call a function on beverage. But in listing 6.5, it appears that we call the function capitalize on the output of readLine rather than on beverage. So it is readLine’s output that we aren’t properly dealing with the possibility of being null, rather than beverage, per se (as later described on page 87). If I’m confused, please help me to follow. This impacts my understanding of other content as I read further into the chapter.