Suggested by @bmwiedemann.

• I signed and returned the Zope Contributor Agreement, and received and accepted an invitation to join a team in the zopefoundation GitHub organization.
• I verified there aren't any other open pull requests for the same change.
• I followed the guidelines in Developer guidelines.
• I successfully ran code quality checks on my changes locally.
• I successfully ran tests on my changes locally.
• If needed, I added new tests for my changes.
• If needed, I added documentation for my changes.
• I included a change log entry in my commits.