It seems that the Pull Request (PR) details are undefined or missing. To create a summary for the PR in the Thanos project, I would need specific information about its changes, objectives, and context. Here are some common elements typically included in a PR summary:

  1. Title of the Pull Request: A brief description of what the PR addresses.
  2. Description: An overview of the changes proposed, including the problem being solved or feature being added.
  3. Motivation: Explanation of why these changes are necessary.
  4. Implementation Details: Technical details about how the changes were implemented, including any key classes, methods, or tools used.
  5. Testing: Any tests that have been written or updated to validate the changes.
  6. Impact: Any potential impact on existing features, performance considerations, or architectural implications.
  7. Dependencies: Any related PRs or issues, or dependencies that must be resolved.

If you can provide more context or content from the PR, I would be happy to help you craft a specific summary!