Listing 2.20 and 2.21's code may need to be switched #878
Description
The title for Listing 2.19 and Listing 2.20 are identical though the one for Listing 2.20 appears to be the one that's incorrect.
It appears the code for Listing 2.21 needs to instead be swapped with the code in Listing 2.20 based on both the text surrounding both examples and the Output 2.11 content which appears to align with what is currently the code of Listing 2.20.
Despite the above aligning with the text, the test names also don't line up with the content so I'm not sure if the text even should be in that order to begin with given the previous commits to those sections were movement from 2.09.
If someone can confirm the final intended order / changes desired I'm happy to submit a PR to correct this!
Really appreciate the book and it's availability online @MarkMichaelis !