Add tests for bulk aggregation

[roywilly]

Issue

Link to the issue resolved by this PR.

Short description

Short description of the approach taken to solve the issue

Pre-review checklist

• [ ] Read through all changes. No redundant print() statements, commented-out code, or other remnants from the development. 👀
• [ ] Make sure tests pass after every commit. ✅
• [ ] New/refactored code is following same conventions as the rest of the code base. 🧬
• [ ] New/refactored code is tested. ⚙
• [ ] Documentation has been updated 🧾

Pre-merge checklist

• [ ] Commit history is consistent and clean. 👌