Bring the doc string in diffdeb up to date.
Bring the doc string in diffdeb up to date.

Per Ping's comment in
https://github.com/projectbuendia/buendia/pull/106#discussion_r294526691

projectbuendia/buendia,projectbuendia/buendia,projectbuendia/buendia,projectbuendia/buendia,projectbuendia/buendia