Improve readability for batched session router tests

[filmakarov]

Improved readability for batched session router tests

Change Type

• [x] Refactor

Checklist

• [x] My code follows this project's style guidelines
• [x] I've reviewed my own code
• [x] I've added comments for any hard-to-understand areas
• [x] I've updated the documentation if necessary
• [x] My changes generate no new warnings
• [x] I've added tests that prove my fix is effective or my feature works
• [x] All unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published