feature #3743 Improve examples in parent services (WouterJ)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #3743).

Discussion
----------

Improve examples in parent services

The code examples were not readable. That isn't a good thing for the documentation :)

| Q   | A
| --- | ---
| Doc fix? | yes
| New docs? | no
| Applies to | all
| Fixed tickets | -

Commits
-------

0535e18 Reworded article a bit
a54ffed Made code readable