Then go to the Cache Storage pane on the Application panel of DevTools. Expand the section and you should see the name of your app shell and data cache listed on the left-hand side. Opening the data cache should should the data stored for each city.
Thanks for the feedback. I've rewritten the codelab from scratch and believe I have fixed this issue. The code has been updated, and the new guide is now live.
If you find any issues with the new codelab, please let us know!
Then go to the Cache Storage pane on the Application panel of DevTools. Expand the section and you should see the name of your app shell and data cache listed on the left-hand side. Opening the data cache should should the data stored for each city.