Fix tutorial

[soininen]

Tutorial was still using the outdated class_name and byname fields.

Closes #318

Checklist before merging

• [x] Documentation (also in Toolbox repo) is up-to-date
• [x] Release notes in Toolbox repo have been updated
• [x] Unit tests have been added/updated accordingly
• [x] Code has been formatted by black
• [x] Unit tests pass

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (0fe0362) 77.07% compared to head (7583f0d) 77.07%.

:exclamation: Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## 0.8-dev #335 +/- ## ======================================== Coverage 77.07% 77.07% ======================================== Files 74 74 Lines 9205 9205 Branches 1944 1944 ======================================== Hits 7095 7095 Misses 1778 1778 Partials 332 332 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.