Iox 5 add more tests

[elBoberido]

Pre-Review Checklist for the PR Author

1. Code follows the Rust coding style and is formatted with rustfmt
2. Branch follows the naming format (iox-123-this-is-a-branch)
3. Commits messages are according to this guideline
   • Commit messages have the issue ID (iox-#42 commit text)
   • Commit author matches Eclipse Contributor Agreement (and ECA is signed)
4. Update the PR title
   • Follow the same conventions as for commit messages
   • Link to the relevant issue
5. Relevant issues are linked
6. Add sensible notes for the reviewer
7. All checks have passed (except task-list-completed)
8. Assign PR to reviewer

Notes for Reviewer

Add a few more tests, update documentation and a small API adjustment

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Code according to our coding style and naming conventions
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

• Relates to Create integration tests #5