It appears that there is no specific information provided about the undefined Pull Request for the Thanos project. To create a meaningful summary, I would need details such as:

1. The title and description of the Pull Request.
2. The main changes or features being introduced.
3. Any associated issues or enhancements.
4. The impact of these changes on the existing codebase or functionality.
5. Any specific areas that require review or testing.
6. Relevant links or references (e.g., related PRs, documentation updates).

If you can provide any of this information or clarify the request, I’d be happy to help you create a comprehensive summary targeted for advanced developers.